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Jun 222015
 
Photo: Joseph Hill/Flickr (Creative Commons)

Groundnut plants growing in Senegal.

Across Africa, governments and scientists alike are heralding groundnuts’ potential to lead resource-poor farmers out of poverty.

Around 5,000 years ago in the north of Argentina, two species of wild groundnuts got together to produce a natural hybrid. The result of this pairing is the groundnut grown today across the globe, particularly in Africa and Asia. Now, scientists are discovering the treasures hidden in the genes of these ancient ancestors.

Nearly half of the world’s groundnut growing area lies within the African continent, yet Africa’s production of the legume has, until recently, accounted for only 25 percent of global yield. Drought, pests, diseases and contamination are all culprits in reducing yields and quality. But through the CGIAR Generation Challenge Programme (GCP), scientists have been developing improved varieties using genes from the plant’s ancient ancestors. These new varieties are destined to make great strides towards alleviating poverty in some of the world’s most resource-poor countries.

Photo: Bill & Melinda Gates Foundation

A Ugandan farmer at work weeding her groundnut field.

A grounding in the history of Africa’s groundnuts

From simple bar snack in the west to staple food in developing countries, groundnuts – also commonly known as peanuts – have a place in the lives of many peoples across the world. First domesticated in the lush valleys of Paraguay, groundnuts have been successfully bred and cultivated for millennia. Today they form a billion-dollar industry in China, India and the USA, while also sustaining the livelihoods of millions of farming families across Africa and Asia.

Groundnut facts and figures •	About one-third of groundnuts produced globally are eaten and two-thirds are crushed for oil  •	The residue from oil processing is used as an animal feed and fertiliser •	Oils and solvents derived from groundnuts are used in medicines, textiles, cosmetics, nitro-glycerine, plastics, dyes, paints, varnishes, lubricating oils, leather dressings, furniture polish, insecticides and soap •	Groundnut shells are used to make plastic, wallboard, abrasives, fuel, cellulose and glue; they can also be converted to biodiesel

“The groundnut is one of the most important income-generating crops for my country and other countries in East Africa,” says Malawian groundnut breeder Patrick Okori, Principal Scientist at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), who was also GCP’s Product Delivery Coordinator for groundnuts.

“It’s like a small bank for many smallholder farmers, one that can be easily converted into cash, fetching the highest prices,” he says.

The situation is similar in West Africa, according to groundnut breeder Issa Faye from the Institut Sénégalais de Recherches Agricoles (ISRA; Senegalese Agricultural Research Institute), who has been involved in GCP since 2008. “It’s very important for Senegal,” he says. “It’s the most important cash crop here – a big source of revenue for farmers around the country. Senegal is one of the largest exporters of peanut in West Africa.”

Groundnuts have good potential for sustaining a strong African export industry in future, while providing a great source of nutrition for Africa’s regional farming families.

“We believe that by using what we have learnt through GCP, we will be able to boost the production and exportation of groundnuts from Senegal to European countries, and even to Asian countries,” says Issa. “So it’s very, very important for us.”

Photo: Joseph Hill/Flickr (Creative Commons)

Harvested groundnuts in Senegal.

How Africa lost its groundnut export market

Photo: V Vadez

Groundnuts in distress under drought conditions.

In Africa, groundnuts have mostly been grown by impoverished smallholder farmers, in infertile soils and dryland areas where rainfall is both low and erratic. Drought and disease cause about USD 500 million worth of losses to groundnut production in Africa every year.

“Because groundnut is self-pollinating, most of the time poor farmers can recycle the seed and keep growing it over and over,” Patrick says. “But for such a crop you need to refresh the seed frequently, and after a certain period you should cull it. So the absence of, or limited access to, improved seed for farmers is one of the big challenges we have. Because of this, productivity is generally less than 50 percent of what would be expected.”

Photo: S Sridharan/ICRISAT

Rosette virus damage to groundnut above and below ground.

Diseases such as the devastating groundnut rosette virus – which is only found in Africa and has been known to completely wipe out crops in some areas – as well as pests and preharvest seed contamination have all limited crop yields and quality and have subsequently shut out Africa’s groundnuts from export markets.

The biggest blow for Africa came in the 1980s from a carcinogenic fungal toxin known as aflatoxin, explains Patrick.

Photo: IITA

Aflatoxin-contaminated groundnut kernels from Mozambique.

Aflatoxin is produced by mould species of the genus Aspergillus, which can naturally occur in the soil in which groundnuts are grown. When the fungus infects the legume it produces a toxin which, if consumed in high enough quantities, can be fatal or cause cancer. Groundnut crops the world over are menaced by aflatoxin, but Africa lost its export market because of high contamination levels.

“That’s why a substantial focus of the GCP research programme has been to develop varieties of groundnuts with resistance to the fungus,” says Patrick.

After a decade of GCP support, a suite of new groundnut varieties representing a broad diversity of characteristics is expected to be rolled out in the next two or three years. This suite will provide a solid genetic base of resistance from which today’s best commercial varieties can be improved, so the levels of aflatoxin contamination in the field can ultimately be reduced.

Ancestral genes could hold the key to drought tolerance and disease resistance

In April 2014, the genomes of the groundnut’s two wild ancestral parents were successfully sequenced by the International Peanut Genome Initiative – a multinational group of crop geneticists, who had been working in collaboration for several years.

The sequencing work has given breeders access to 96 percent of all groundnut genes and provided the molecular map needed to breed drought-tolerant and disease-resistant higher-yielding varieties, faster.

“The wild relatives of a number of crops contain genetic stocks that hold the most promise to overcome drought and disease,” says Vincent Vadez, ICRISAT Principal Scientist and groundnut research leader for GCP’s Legumes Research Initiative. And for groundnut, these stocks have already had a major impact in generating the genetic tools that are key to making more rapid and efficient progress in crop breeding.

“Genetically, the groundnut has always been a really tough nut to crack,” says GCP collaborator David Bertioli, from the University of Brasilia in Brazil. “It has a complex genetic structure, narrow genetic diversity and a reputation for being slow and difficult to breed. Until its genome was sequenced, the groundnut was bred relatively blindly compared to other crops, so it has remained among the less studied crops,” he says.

With the successful genome sequencing, however, researchers can now understand groundnut breeding in ways they could only dream of before.

Photo: N Palmer/CIAT

Groundnut cracked.

“Working with a wild species allows you to bring in new versions of genes that are valuable for the crop, like disease resistance, and also other unexpected things, like improved yield under drought,” David says. “Even things like seed size can be altered this way, which you don’t really expect.”

The sequencing of the groundnut genome was funded by The Peanut Foundation, Mars Inc. and three Chinese academies (the Chinese Academy of Agricultural Sciences, the Henan Academy of Agricultural Sciences, and the Shandong Academy of Agricultural Sciences), but David credits GCP work for paving the way. “GCP research built up the populations and genetic maps that laid the groundwork for the material that then went on to be sequenced.”

Chair of GCP’s Consortium Committee, David Hoisington – formerly ICRISAT’s Director of Research and now Senior Research Scientist and Program Director at the University of Georgia – says the sequencing could be a huge step forward for boosting agriculture in developing countries.

“Researchers and plant breeders now have much better tools available to breed more productive and more resilient groundnut varieties, with improved yields and better nutrition,” he says.

These resilient varieties should be available to farmers across Africa within a few years.

Genetics alone will not lift productivity – farmers’ local knowledge is vital

Improvements in the yield, quality and share of the global market of groundnuts produced by developing countries are already being seen as a result of GCP support, says Vincent Vadez. “But for this trend to continue, the crop’s ability to tolerate drought and resist diseases must be improved without increasing the use of costly chemicals that most resource-poor farmers simply cannot afford,” he says.

While genetic improvements are fundamental to developing the disease resistance and drought tolerance so desperately needed by African farmers, there are other important factors that can influence the overall outcome of a breeding programme, he explains. Understanding the plant itself, the soil and the climate of a region are all vital in creating the kinds of varieties farmers need and can grow in their fields.

Photo: Y Wachira/Bioversity International

Kenyan groundnut farmer Patrick Odima with some of his crop.

“I have grown increasingly convinced that overlooking these aspects in our genetic improvements would be to our peril,” Vincent warns. “There are big gains to be made from looking at very simple sorts of agronomic management changes, like sowing density – the number of seeds you plant per square metre. Groundnuts are often cultivated at seeding rates that are unlikely to achieve the best possible yields, especially when they’re grown in infertile soils.”

For Omari Mponda, now Director of Tanzania’s Agricultural Research Institute at Naliendele (ARI–Naliendele), previously Zonal Research Coordinator and plant breeder, and country groundnut research leader for GCP’s Tropical Legumes I project (TLI; see box below), combining good genetics with sound agronomic management is a matter of success or failure for any crop-breeding programme, especially in poverty-stricken countries.

“Molecular markers by themselves will not address the productivity on the ground,” he says, agreeing with Vincent. “A new variety of groundnut may have very good resistance, but its pods may be too hard, making shelling very difficult. This does not help the poor people, because they can’t open the shells with their bare hands.”

And helping the poor of Africa is the real issue, Omari says. “We must remind ourselves of that.”

This means listening to the farmers: “It means finding out what they think and experience, and using that local knowledge. Only then should the genetics come in. We need to focus on the connections between local knowledge and scientific knowledge. This is vital.”

The Tropical Legumes I project (TLI) was initiated by GCP in 2007 and subsequently incorporated into the Programme’s Legumes Research Initiative (RI). The goal of the RI was to improve the productivity of four legumes – beans, chickpeas, cowpeas and groundnuts – that are important in food security and poverty reduction in developing countries, by providing solutions to overcome drought, poor soils, pests and diseases. TLI was led by GCP and focussed on Africa. Work on groundnut within TLI was coordinated by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). The partners in the four target countries were Malawi’s Chitedze Research Station, Senegal’s Institut Sénégalais de Recherches Agricoles (ISRA), and Tanzania’sAgricultural Research Institute (ARI). Other partners were France’s Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), the Brazilian Corporation of Agricultural Research (EMBRAPA) and Universidade de Brasil in Brazil, and University of Georgia in the USA. Tropical Legumes II (TLII) was a sister project to TLI, led by ICRISAT on behalf of the International Institute of Tropical Agriculture (IITA) and International Center for Tropical Agriculture (CIAT). It focussed on large-scale breeding, seed multiplication and distribution primarily in sub-Saharan Africa and South Asia, thus applying the ‘upstream’ research results from TLI and translating them into breeding materials for the ultimate benefit of resource-poor farmers. Many partners in TLI also worked on projects in TLII.

Photo: A Diama/ ICRISAT

Participants at a farmer field day in Mali interact with ICRISAT staff and examine different groundnut varieties and books on aflatoxin control and management options.

Local knowledge and high-end genetics working together in Tanzania

Like Malawi, Tanzania has also experienced the full spectrum of constraints to groundnut production – from drought, aflatoxin contamination, poor soil and limited access to new seed, to a lack of government extension officers visiting farmers to ensure they have the knowledge and skills needed to improve their farming practices and productivity.

Although more than one million hectares of Tanzania is groundnut cropping land, the resources supplied by the government have until now been minimal, says Omari, compared to those received for traditional cash crops such as cashews and coffee.

Photo: C Schubert/CCAFS

A farmer and her children near Dodoma, Tanzania, an area where climate change is causing increasing heat and drought. Groundnut is an important crop for local famers, forming the basis of their livelihood together with maize and livestock.

“But the groundnut is now viewed differently by the government in my country as a result of GCP’s catalytic efforts,” Omari says. “More resources are being put into groundnut research.”

In the realm of infrastructure, for instance, the use of GCP funds to build a new irrigation system at Naliendele has since prompted Tanzania’s government to invest further in irrigation for breeder seed production.

“They saw it was impossible for us to irrigate our crops with only one borehole, for instance, so they injected new funds into our irrigation system. We now have two boreholes and a whole new system, which has helped expand the seed production flow. Without GCP, this probably wouldn’t have happened.”

Irrigation, for Omari, ultimately means being able to get varieties to the farmers much faster: “maybe three times as fast,” he says. “This means we’ll be able to speed up the multiplication of seeds – in the past we were relying on rainfed seed, which took longer to bulk and get to farmers.”

With such practical outcomes from GCP’s research and funding efforts and the new genetic resources becoming available, breeders like Omari see a bright future for groundnut research in Tanzania.

Photo: C Schubert/CCAFS

Groundnut farmer near Dodoma, Tanzania.

The gains being made at Naliendele are not only sustainable, Omari explains, but have given the researchers independence and autonomy. “Before we were only learning – now we have become experts in what we do.”

Prior to GCP, Omari and his colleagues were used to conventional breeding and lacked access to cutting-edge science.

“We used to depend on germplasm supplied to us by ICRISAT, but now we see the value in learning to use molecular markers in groundnut breeding to grow our own crosses, and we are rapidly advancing to a functional breeding programme in Tanzania.”

Omari says he and his team now look forward to the next phase of their research, when they expect to make impact by practically applying their knowledge to groundnut production in Tanzania.

Similar breeding success in Senegal

Photo: C Schubert/CCAFS

Harvesting groundnuts in Senegal.

Issa Faye became involved in GCP in 2008 when the programme partly funded his PhD in fresh seed dormancy in groundnuts. “I was an example of a young scientist who was trained and helped by GCP in groundnut research,” he says.

“I remember when I was just starting my thesis, my supervisor would say, ‘You are very lucky because you will not be limited to using conventional breeding. You are starting at a time when GCP funding is allowing us to use marker-assisted selection [MAS] in our breeding programme’.”

The importance of MAS in groundnut breeding, Issa says, cannot be overstated.

“It is very difficult to distinguish varieties of cultivated groundnut because most of them are morphologically very similar. But if you use molecular markers you can easily distinguish them and know the diversity of the matter you are using, which makes your programme more efficient. It makes it easier to develop varieties, compared to the conventional breeding programme we were using before we started working with GCP.”

By using markers that are known to be linked to useful genes for traits such as drought tolerance, disease resistance, or resistance to aflatoxin-producing fungi, breeders can test plant materials to see whether or not they are present. This helps them to select the best parent plants to use in their crosses, and accurately identify which of the progeny have inherited the gene or genes in question without having to grow them all to maturity, saving time and money.

Photo: S Sridharan/ICRISAT

These women in Salima District, Malawi, boil groundnuts at home and carry their tubs to the Siyasiya roadside market.

Senegal, like other developing countries, does not have enough of its own resources for funding research activities, explains Issa. “We can say we are quite lucky here because we have a well-developed and well-equipped lab, which is a good platform for doing molecular MAS. But we need to keep improving it if we want to be on the top. We need more human resources and more equipment for boosting all the breeding programmes in Senegal and across other regions of West Africa.”

Recently, Issa says, the Senegalese government has demonstrated awareness of the importance of supporting these activities. “We think that we will be receiving more funds from the government because they have seen that it’s a kind of investment. If you want to develop agriculture, you need to support research. Funding from the government will be more important in the coming years,” he says.

“Now that we have resources developed through GCP, we hope that some drought-tolerant varieties will come and will be very useful for farmers in Senegal and even for other countries in West Africa that are facing drought.”

It’s all about poverty

“The achievements of GCP in groundnut research are just the beginning,” says Vincent. The legacy of the new breeding material GCP has provided, he says, is that it is destined to form the basis of new and ongoing research programmes, putting research well ahead of where it would otherwise have been.

“There wasn’t time within the scope of GCP to develop finished varieties because that takes such a long time, but these products will come,” he says.

For Vincent, diverse partnerships facilitated by GCP have been essential for this to happen. “The groundnut work led by ICRISAT and collaborators in the target countries – Malawi, Senegal, and Tanzania – has been continuously moving forward.”

Photo: S Sridharan/ICRISAT

Groundnut harvesting at Chitedze Agriculture Research Station, Malawi.

Issa agrees: “It was fantastic to be involved in this programme. We know each other now and this will ease our collaborations. We hope to keep working with all the community, and that will obviously have a positive impact on our work.”

For Omari, a lack of such community and collaboration can only mean failure when it comes to addressing poverty.

“If we all worked in isolation, a lot of money would be spent developing new varieties but nothing would change on the ground,” he says. “Our work in Tanzania is all about the problem of poverty, and as scientists we want to make sure the new varieties are highly productive for the farmers around our area. This means we need to work closely with members of the agricultural industry, as a team.”

Omari says he and his colleagues see themselves as facilitators between the farmers of Tanzania and the ‘upstream end’ of science represented by ICRISAT and GCP. “We are responsible for bringing these two ends together and making the collaboration work,” he says.

Only from there can we come up with improved technologies that will really succeed at helping to reduce poverty in Africa.”

As climate change threatens to aggravate poverty more and more in the future, the highly nutritious, drought-tolerant groundnut may well be essential to sustain a rapidly expanding global population.

By developing new, robust varieties with improved adaptation to drought, GCP researchers are well on the way to increasing the productivity and profitability of the groundnut in some of the poorest regions of Africa, shifting the identity of the humble nut to potential crop champion for future generations.

More links

Photo: S Sridharan/ICRISAT

Oswin Madzonga, Scientific Officer at ICRISAT-Lilongwe, visits on-farm trials near Chitala Research Station in Salima, Malawi, where promising disesase-resistant varieties are being tested real life conditions.

Jun 192015
 
Photo: N Palmer/CIAT

Bean Market in Kampala, Uganda.

Common beans are the world’s most important food legume, particularly for subsistence and smallholder farmers in East and Southern Africa. They are a crucial source of protein, are easy to grow, are very adaptable to different cropping systems, and mature quickly.

To some, beans are ‘a near-perfect food’ because of their high protein and fibre content plus their complex carbohydrates and other nutrients. One cup of beans provides at least half the recommended daily allowance of folate, or folic acid – a B vitamin that is especially important for pregnant women to prevent birth defects. One cup also supplies 25–30 percent of the daily requirement of iron, 25 percent of that of magnesium and copper, and 15 percent of the potassium and zinc requirement.

Unfortunately, yields in Africa are well below their potential – between 20 and 30 percent below. The main culprit is drought, which affects 70 percent of Africa’s major bean-producing regions. Drought is especially severe in the mid-altitudes of Ethiopia, Kenya, Malawi and Zimbabwe, as well as across Southern Africa.

“For the past seven or eight years, rains have been very unreliable in central and northern Malawi,” says Virginia Chisale, a bean breeder with Malawi’s Department of Agricultural Research and Technical Services.

“In the past, rains used to be very reliable and people were able to know the right time to plant to meet the rains in critical conditions,” she says. “Now these primary agriculture regions are either not receiving rain for long periods of time, or rains are not falling at the right time.”

Virginia recounts that during the 2011/12 cropping season there were no rains soon after planting, when it is important that beans receive moisture. Such instances can cut bean yields by half.

Photo: N Palmer/CIAT

Steve Beebe in the field.

“Drought is a recurrent problem of rainfed agriculture throughout the world,” says Steve Beebe, a leading bean breeder with the International Center for Tropical Agriculture (CIAT). “Since over 80 percent of the world’s cultivated lands are rainfed, drought stress has major implications for global economy and trade.”

Steve was the Product Delivery Coordinator for the beans component of the Legumes Research Initiative (RI), part of Phase II of the CGIAR Generation Challenge Programme (GCP). The RI incorporated several projects, the biggest of which was Tropical Legumes I (TLI) (see box). The main objective of the work on beans within TLI was to identify and develop drought-tolerant varieties using marker-assisted breeding techniques. The resulting new varieties were then evaluated for their performance in Ethiopia, Kenya, Malawi and Zimbabwe.

“It’s vital that we develop high-yielding drought-tolerant varieties so as to help farmers, particularly in developing countries, adapt to drought and produce sustained yields for their families and local economies,” says Steve.

The Tropical Legumes I project (TLI) was initiated by GCP in 2007 and subsequently incorporated into the Programme’s Legumes Research Initiative (RI). The goal of the RI was to improve the productivity of four legumes – beans, chickpeas, cowpeas and groundnuts – that are important in food security and poverty reduction in developing countries, by providing solutions to overcome drought, poor soils, pests and diseases. TLI was led by GCP and focussed on Africa. Work on beans within TLI was coordinated by the International Center for Tropical Agriculture (CIAT). The partners in the four target countries were Ethiopia’s South Agricultural Research Institute (SARI), the Kenya Agricultural Research Institute (now known as the Kenya Agricultural and Livestock Research Organization, KALRO), Malawi’s Department of Agricultural Research and Technical Services (DARTS) and Zimbabwe’s Crop Breeding Institute (CBI) of the Department of Research and Specialist Services (DR&SS). Cornell University in the USA was also a partner. Tropical Legumes II (TLII) was a sister project to TLI, led by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) on behalf of the International Institute of Tropical Agriculture (IITA) and CIAT. It focussed on large-scale breeding, seed multiplication and distribution primarily in sub-Saharan Africa and South Asia, thus applying the ‘upstream’ research results from TLI and translating them into breeding materials for the ultimate benefit of resource-poor farmers. Many partners in TLI also worked on projects in TLII.

For an overview of the work on beans from the perspectives of four different partners, watch our video below, “The ABCs of bean breeding”.

What makes a plant drought tolerant?

The question of what makes a plant drought tolerant is one that breeders have debated for centuries. No single plant characteristic or trait can be fully responsible for protecting the plant from the stress of intense heat and reduced access to water.

“It’s a difficult question to answer for any plant, including beans,” says Steve. “Once you do isolate a trait genetically, it can often be difficult to identify this trait in a plant in the field, for example, identifying the architecture and length of a plant’s roots.”

Phenotyping is an important process in conventional plant breeding. It involves identifying and measuring the presence of physical traits such as seed colour, pod size, stem thickness or root length. Gathering data about a range of such characteristics across a number of different plant lines helps breeders decide which plants to use as parents in crosses and which of the progeny have inherited useful traits.

Root length has long been thought of as a drought-tolerance trait: the longer the root, the more chance it has of tapping into moisture stored deeper in the soil profile.

Given, however, that it is difficult to inspect root length in the field, researchers at CIAT have been exploring other more accessible drought-tolerance traits they can more easily identify and measure. One of these is measuring the weight of the plants’ seeds.

Photo: N Palmer/CIAT

Comparison between varieties in trials of drought tolerant beans at CIAT’s headquarters in Colombia.

Fat beans indicate plants coping with drought stress

“We measure seed weight because we are discovering that under drought stress, drought-tolerant bean varieties will divert sugars from their leaves, stems and pods to their seed,” says Steve. “We call this trait ‘pod filling’, and for us it is the most important drought-tolerance trait to be found over the last several years.”

Finding bean plants with larger, heavier seeds when growing under drought conditions indicates that the plants are coping well, and means farmers’ yields are maintained.

As part of GCP’s Legumes RI, African partners like Virginia have been measuring the seed weight of several advanced breeding lines, which can be used as parents to develop new varieties. These breeding lines have been bred by CIAT and demonstrate this pod-filling process and consequent tolerance of drought.

Although this measurement is relatively cheap and easy for breeders all over the world to do, Steve and his team are interested in finding an even more efficient way to spot plants that maintain full pods under drought.

“We are trying to understand which genes control this trait so we can use molecular-assisted breeding techniques to determine when the trait is present,” says Steve. Having identified several regions of genes related to pod filling, he and his team have developed molecular markers to help breeders identify which plants have these desired genes. “The use of molecular markers in selection significantly reduces the time and cost of the breeding process, making it more efficient. This means that we get improved varieties out to farmers more quickly.”

Photo: N Palmer/CIAT

Bean farmer in Rwanda.

Molecular markers (also known as DNA markers) are used by researchers as ‘flags’ to identify particular genes within a plant’s genome (DNA) that control desired traits, such as drought tolerance. These markers are themselves fragments of DNA that highlight particular genes or regions of genes by binding near them.

To use an analogy, think of a story as the plant’s genome: its words are the plant’s genes, and a molecular marker works like a text highlighter. Molecular markers are not precise enough to highlight specific words (genes), but they can highlight sentences (genomic regions) that contain these words (genes), making it easier and quicker to identify whether or not they are present.

Photo: J D'Amour/HarvestPlus

Beans from Rwanda.

Plant breeders can use molecular markers from early on in the breeding process to choose parents for their crosses and determine whether progeny they have produced have the desired trait, based on testing only a small amount of seed or seedling tissue.

“If the genes are present, we grow the progeny and conduct the appropriate phenotyping; if not, we throw the progeny away,” explains Steve. “This saves us resources and time because we need to grow and phenotype only the few hundred progeny which we know have the desired genes, instead of a few thousand progeny, most of which would not possess the gene.”

Outsourcing genotyping to the UK Steve says a significant contribution made by GCP was facilitating a deal with a private UK company (LGC Genomics, formerly KBioscience) that is able to quickly and cheaply genotype leaf samples sent to them by African breeders. The company then forwards the data to the International Center for Tropical Agriculture (CIAT), who analyse it and let the breeders in Africa know which progeny contain the desired genes and are suitable for breeding, and which ones to throw away.  “The whole process takes roughly four weeks, but saves the breeders the time and effort to grow all progeny,” says Steve. “This system works well for countries that don’t have the capacity or know-how to do the molecular work,” says Darshna Vyas, a plant genetics specialist with LGC Genomics. “Genotyping has advanced to a point where even larger labs around the world choose to outsource their genotyping work, as it is cheaper and quicker than if they were to equip their lab and do it themselves. We do hundreds of thousands of genotyping samples a day – day in, day out. It’s our business.”

GCP has supported this foundation work, building on the extensive bean research already done by CIAT dating back to the 1970s, to develop molecular markers not only for drought-tolerance traits such as pod filling, but also for traits associated with resistance to important insect and disease menaces.

“Under drought conditions, plants become more susceptible to pests and diseases, so it was important that we also try to identify and include resistance traits in the drought-tolerant progeny,” says Steve.

Drought is but one plant stressor – diseases and pests wreak havoc too

Photo: W Arinaitwe/CIAT/PABRA

Common bacterial blight on bean.

The bean diseases that farmers in Ethiopia, Kenya, Malawi and Zimbabwe continually confront are angular leaf spot, bean common mosaic virus, common bacterial blight and rust. Key insect pests are bean stem maggot and aphids.

“We’ve had reports of bean stem maggot and bean common mosaic virus wiping out a whole field of beans,” says Virginia. “Although angular leaf spot and common bacterial blight are not as damaging, they can still reduce yields by over 50 percent.”

Virginia says this is devastating for farmers in Malawi, many of whom only have enough land and money to grow beans to feed their families and sell what little excess there is at market to purchase other necessities.

“This is why we are excited by the prospect of developing not just drought-tolerant varieties, but drought-tolerant varieties with disease and pest resistance as well,” says Virginia.

Virginia’s team in Malawi – along with other breeders in Ethiopia, Kenya and Zimbabwe – are currently using over 200 Mesoamerican and Andean bean breeding lines supplied by CIAT to help breed for drought tolerance and disease and pest resistance. Although many do not yet have the capacity to do molecular breeding in their countries, thanks to advances in plant science it is becoming more feasible and cheaper to outsource molecular breeding stages of the process (see box above).

“With help from GCP and CIAT, we have successfully crossed a line from CIAT with some local varieties to produce plants that are high yielding and resistant to most common bean diseases,” Virginia says.

Photo: ILRI

Malawian farmer Jinny Lemson grows beans to feed her livestock.

Ethiopia’s new bean breeders

Photo: ILRI

Young women sorting beans after a harvest in Ethiopia.

One man who has been helping build this new breeding capacity is Bodo Raatz, a molecular geneticist who joined CIAT and GCP’s Legumes RI in late 2011.

“We’ve [CIAT] hosted several African PhD students here in Colombia and have conducted several workshops in Colombia and Africa too,” says Bodo.

“At the workshops we teach local breeders and technicians how to use genetic tools and markers for advanced breeding methods, phenotyping and data management. The more people there are who can do this work, the quicker new varieties will filter through to farmers.”

Bodo says he has found delivering the training both personally and professionally rewarding, especially “seeing the participants understand the concepts and start using the tools and techniques to develop new lines [of bean varieties] and contribute to the project.”

One national breeder whom Bodo has seen advance from the training is Daniel Ambachew, then a bean breeder at the Southern Agricultural Research Institute (SARI) in Ethiopia.

Daniel started as a GCP-funded Master’s student enrolled at Haramaya University, Ethiopia, evaluating bean varieties with both tolerance to drought and resistance to bean stem maggot. He eventually became the Ethiopian project leader for beans within GCP’s Legumes RI.

“Daniel is currently one of only a handful of bean breeders in Ethiopia who are using molecular-assisted breeding techniques to breed new varieties,” says Bodo. “It’s quite an achievement, especially now that he has taken on the lead role in Ethiopia.”

Photo: N Palmer/CIAT

Buying and selling at a bean market in Kampala, Uganda.

For Daniel, learning about and using the new molecular-breeding techniques has been an exciting new challenge. “The most interesting part of the technology is that it helps us understand what is going on in the plant at a molecular level and lets us know if the crosses we are making are successful and the genes we want are present,” says Daniel. “All this helps improve our efficiency and speeds up the time it takes us to breed and release new varieties for farmers.”

By the end of 2014, Daniel and his team had finished the third year of trials and had several drought-tolerant lines ready for national trials in 2015 and eventual release in 2016.

Between 2012 and 2014, Daniel, and two other breeders from SARI, attended GCP’s three-year Integrated Breeding Multiyear Course, learning how to design molecular-assisted breeding trials; collect, analyse and interpret genotypic and phenotypic data from the trials; and manage data using the GCP’s Integrated Breeding Platform (IBP), particularly its Breeding Management System (BMS).

“The IBP is a really fantastic tool,” says Daniel. “During the course we learnt about the importance of recording clear and consistent phenotypic data, and the IBP helps us to do this as well as store it in a database. It makes it easier to refer to and learn from the past. I’m now trying to pass on the knowledge I’ve learnt as well as create and implement a data-management policy for all plant breeders and technicians in our institute.”

Bodo agrees with Daniel about the importance of IBP and believes it will be a true legacy of GCP beyond the Programme’s end in 2014. “The Platform has been designed to be the main data-management platform for plant breeders. It allows breeders to talk the same language and will reduce the need for learning new systems.”

Daniel says the challenge for his institute now is to build further capacity among staff – and to retain it. “At the moment we only have two bean breeders,” says Daniel. “It’s hard to retain research staff in Ethiopia as salaries are very low, so people move on to new, higher paying positions when they get the chance. It’s not unique to Ethiopia, but true of all Africa.”

Photo: O Thiong'o/CIAT/PABRA

Bean trials at KALRO in Kenya.

Kenya chasing higher bean yields

Across the border, Kenya has also been facing staffing issues.

“We are behind Ethiopia, Malawi and Zimbabwe in terms of our capacity and our trials,” says David Karanja, a bean breeder and project leader at the Kenya Agricultural and Livestock Research Organisation (KALRO, formerly the Kenya Agricultural Research Institute, or KARI). “At the start of the project, we didn’t have a breeder to lead the project for almost two years. However, we are now rapidly catching up with the others.”

And it’s a good thing too, as the country is in need of higher yielding beans to accommodate its population’s insatiable appetite for the crop. Out of the four target African countries, Kenya is the largest bean producer and consumer. As such, the country relies on beans imports from Ethiopia, Malawi, Tanzania and Uganda.

“A lot of families eat beans every day,” says David. “On average, the population eats 14–16 kilograms per person each year, but in western Kenya the average is over 60 kilograms.”

Photo: CIMMYT

Githeri, a Kenyan staple food made with maize and beans.

Kenyans consume an average total of 400,000 tonnes of beans each year, consistently more than the country produces. Projected trends in population growth indicate that this demand for beans will continue to increase by three to four percent annually.

Even though the area planted to beans has been increasing, David says farmers and breeders need to work together to improve productivity, which is well below where it should be. “The national average yield is 100 kilograms per hectare, which can range from 50 kilograms up to 700 kilograms, depending on whether we experience a drought, or a pest or disease epidemic,” explains David. “The minimum target we should be aiming for is 1,200 kilograms per hectare.”

Such a figure may seem impossible, but David believes that new breeding techniques and the varieties KALRO are producing with the help of CIAT are providing hope that farmers can reach these lofty goals.

“We have several bean lines that are showing good potential to produce higher yields under drought conditions and also have resistance to diseases like rust and mosaic virus,” says David. “They are currently under national trials, and we are confident these will be released to farmers in 2015.”

Photo: O Thiong'o/CIAT/PABRA

Varieties fare differently in KALRO bean trials in Kenya.

Commercialising beans

Photo: CIAT

Maturing bean pods.

“Many subsistence farmers have limited access to good quality bean seeds; they lack knowledge of good crop, pest and disease management; and they have poor post-harvest storage facilities,” says Godwill Makunde, who was previously a breeder at Zimbabwe’s Crop Breeding Institute (CBI) and leader of GCP’s Legumes RI bean project in Zimbabwe.

TLI’s sister project, Tropical Legumes II (TLII, see box above), led by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), provided the route by which the upstream work of TLI would have impact in helping these farmers, seeking to deliver the new varieties developed under TLI into their hands. As part of TLII, Godwill, his successor Bruce Mutari, and other African partners worked on developing sustainable seed systems.

“Because beans are self-pollinating, which means each crop is capable of producing seed exactly as it was sown, farmers tend to propagate seed on farm,” says Godwill. “While this can be cost effective, it can reduce farmers’ access to higher yielding, tolerant lines, like the ones we are currently producing.”

In none of the partner countries of TLI and TLII are there formal systems for producing and disseminating bean seeds. Godwill and other partners are working with seed companies on developing a sustainable model where both farmers and seed companies can benefit.

Success built on a solid foundation

Photo: N Palmer/CIAT

Field workers tend beans in Rwanda.

A key to the success of the beans component of GCP’s Legumes RI, according to Ndeye Ndack Diop, GCP’s Capacity Building Theme Leader and TLI Project Manager, has been partners’ existing relationships with each other.

“Many of the partners are part of a very strong network of bean breeders: the Bean Coordinated Agricultural Project [BeanCAP],” explains Ndeye Ndack, adding that the TLI and BeanCAP networks benefited each other.

BeanCAP released more than 1,500 molecular markers to TLI researchers, which have helped broaden the genetic tools available to developing-country bean breeders.

TLI was also able to leverage and advance previous BeanCAP work and networks. For example, it was through this collaboration that GCP was introduced to LGC Genomics, a company it then worked with on many other crop projects.

To sustain integrated breeding practices beyond the Programme’s close in 2014, GCP established Communities of Practice (CoPs) that are discipline- and commodity-oriented.

“GCP’s CoP for beans has also helped to broaden both the TLI and BeanCAP networks too,” says Ndeye Ndack. “The ultimate goal of the CoPs is to provide a platform for community problem solving, idea generation and information sharing.”

Developing physical capacity

Besides developing human capacity, GCP has also invested in developing infrastructure in Ethiopia, Kenya and Zimbabwe.

SARI now has an irrigation system to enable them to conduct drought trials year round. “We have 12.5 hectares of irrigation now, which we use to increase our efficiency and secure our research,” says Daniel. “We can also increase seed with this irrigation during the off-season and develop early generation seeds for seed producers.”

In Zimbabwe, CBI received specialised equipment that enables them to extract DNA and send it for genotyping in the UK.

Both SARI and CBI also received automatic weather stations from GCP for high-precision climatic data capture, with automated data loading and sharing with other partners in the network.

Delivering the right beans to farmers

Back in Malawi, Virginia says another important facet of the TLII project is that researchers understand what qualities farmers want in their beans. “It’s no use developing higher yielding beans if the farmer doesn’t like the colour, or they don’t taste nice,” she says. “For example, consumers in central Malawi prefer khaki or ‘sugar beans’, which are tan with brown, black or red speckles. While those in southern Malawi tend to prefer red beans. Farmers know this and will grow beans that they know consumers will want.”

Photo: N Palmer/CIAT

Diversity at bean market in Masaka, Uganda.

Breeders in all four countries have been conducting workshops and small trials with farmers to find out this information. In Kenya, David finds farmer participation a great way to promote the work they are doing and show the impact the new drought-tolerant and disease-resistant lines can have.

“Farmers are excited and want to grow these varieties immediately when they see for themselves the difference in yield these new varieties can produce compared to their regular varieties,” says David. “They understand the pressure on them to produce more yields and are grateful that these varieties are becoming more readily available as well as tailored to their needs.”

For Steve, such anecdotes provide him and his collaborators with incentives to continue their quest to discover more molecular markers associated with drought tolerance, post-GCP.

“It’s a testament to everyone involved that we have been able to develop these advanced lines with pod-filling traits using molecular techniques, and make them available to farmers in six years instead of ten,” says Steve.

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Jun 122015
 
Photo: IITA

Growing cowpea pods.

Each year, millions of people in Senegal go hungry for several months, many surviving on no more than one meal a day. Locals call this time soudure – the hungry period. It typically lasts from June through to September, when previous winter and spring cereal supplies are exhausted and people wait anxiously for a bountiful autumn cereal harvest.

During this period, a bowl of fresh green cowpea pods once a day is the best that many people can hope for. Cowpeas are the first summer crop to mature, with some varieties ready to harvest in as little as 60 days.

While cowpeas provide valued food security in Africa, yields remain low. In Senegal, average cowpea yields are 450 kilograms per hectare, a mere 10–30 percent of their potential. This poor productivity is primarily because of losses due to insects and diseases, but is sometimes further compounded by chronic drought.

In 2007, the CGIAR Generation Challenge Programme (GCP) brought together a team of plant breeders and geneticists from Burkina Faso, Mozambique, Nigeria, Senegal and the USA to collaborate on cowpea. Their goal was to breed varieties that would be higher yielding, drought tolerant and resistant to pests and diseases, and so help secure and improve local cowpea production in sub-Saharan African countries.

Photo: IITA

A trader selling cowpea at Bodija market, Ibadan, Nigeria.

Cowpea production – almost all of it comes from Africa

A type of legume originating in West Africa, cowpeas are also known as niébé in francophone Africa and as black-eyed peas in the USA.  They are well adapted to drier, warmer regions and grow well in poor soils. In Africa, they are mostly grown in the hot, drought-prone savannas and very arid sub-Saharan regions, often together with pearl millet and sorghum.

Nutritionally, cowpeas are a major source of dietary protein in many developing countries. Young leaves, unripe pods and peas are used as vegetables, and the mature grain is processed for various snacks and main meal dishes. As a cash crop, both for grain and animal fodder, cowpea is highly valued in sub-Saharan Africa.

Worldwide, an estimated 14.5 million hectares of land is planted with cowpea each year. Global production of dried cowpeas in 2010 was 5.5 million tonnes, 94 percent of which was grown in Africa.

“In Senegal, cowpeas cover more than 200,000 hectares,” says Ndiaga Cissé, cowpea breeder at L’institut sénégalais de recherches agricoles (ISRA; Senegalese Agricultural Research Institute). “This makes it the second most grown legume in Senegal, after groundnuts.”

In 2011, Senegal experienced its third drought within a decade. Low and erratic rainfall led to poor harvests in 2011 and 2012: yields of cereal crops (wheat, barley and maize) fell by 36 percent compared to 2010. Consequently, the hungry period in 2012 started three months earlier than usual, making gap-fillers like cowpea even more important. In fact, cereal production in sub-Saharan African countries has not seen substantial growth over the last two decades – total area, yield and production grew by only 4.3 percent, 1.5 percent and 5.8 percent, respectively.

Climate change is expected to further compound this situation across sub-Saharan Africa. Droughts are forecast to occur more frequently, weakening plants and making them more vulnerable to pests and diseases.

“Improved varieties of cowpeas are urgently needed to narrow the gap between actual and potential yields,” says Ndiaga. “They will not only provide security to farmers in the face of climate change, but will also help with food security and overall livelihoods.”

Photo: IITA

Farmers in Northern Nigeria transport their cowpea harvest.

Mapping the cowpea genome

For over 30 years, Phil Roberts, a professor in the Department of Nematology at the University of California, Riverside (UCR), has been breeding new varieties of cowpea. “UCR has a long history of research in cowpea breeding that goes back to the mid-seventies,” explains Phil. “One of the reasons we were commissioned by GCP in 2007 was to use our experience, particularly in using molecular breeding, to help African cowpea-breeding programmes produce higher yielding cowpeas.”

For seven years, Phil and his team at UCR coordinated the cowpea component of the Tropical Legumes I (TLI) project led by GCP (see box below).  The objective of this work was to advance cowpea breeding by applying modern, molecular breeding techniques, tools and knowledge to develop lines and varieties with drought tolerance and resistance to pests and diseases in the sub-Saharan African countries Burkina Faso, Mozambique, Nigeria and Senegal.

The molecular breeding technology that UCR uses for cowpeas is based on finding genes that help cowpea plants tolerate insects and diseases, identifying markers that can indicate the presence of known genes, and using these to incorporate valuable genes into higher yielding varieties.

“Using molecular breeding techniques is a lot easier and quicker, and certainly less hit-or-miss, than conventional breeding techniques,” says Phil. “We can shorten the time needed to breed better adapted cowpea varieties preferred by farmers and markets.”

Phil explains that the first priority of the project was to map the cowpea genome.

“The map helps us locate the genes that play a role in expressing key traits such as drought tolerance, disease resistance or pest resistance,” says Phil. “Once we know where these genes are, we can use molecular marker tools to identify and help select for the traits. This is a lot quicker than growing the plant and observing if the trait is present or not.”

To use an analogy, think of the plant’s genome as a story: its words are the plant’s genes, and a molecular marker works as a text highlighter. Molecular markers are not precise enough to highlight specific words (genes), but they can highlight sentences (genomic regions) that contain these words (genes), making it easier and quicker to identify which plants have them. Traditionally, breeders have needed to grow plants to maturity under appropriately challenging conditions to see which ones are likely to have useful traits, but by using markers to flag valuable genes they are able to largely skip this step, and test large amounts of material to choose the best parents for their crosses, then check which of the progeny have inherited the gene or genes.

Photo: IITA

Diversity of cowpea seed.

Breeding new varieties faster, using modern techniques

Photo: ICRISAT

A farmer pleased with her cowpea plants.

The main focus of the cowpea component in TLI was to optimise marker-assisted recurrent selection (MARS) and marker-assisted backcrossing (MABC) breeding techniques for sub-Saharan African environments and relevant traits.

MARS identifies regions of the genome that control important traits. In the case of cowpeas, these include drought tolerance and insect resistance. It uses molecular markers to explore more combinations in the plant populations, thus increasing breeding efficiency.

MABC is the simplest form of marker-assisted breeding, in which the goal is to incorporate a major gene from an agronomically inferior source (the donor parent) into an elite cultivar or breeding line (the recurrent parent). Major genes by themselves have a significant effect; it’s therefore easier to find a major gene associated with a desired trait, than having to find and clone several minor genes. The aim is to produce a line made up almost entirely of the recurrent parent genotype, with only the selected major gene from the donor parent.

Using the genome map and molecular markers, the UCR team identified 30 cowpea lines with drought tolerance and pest resistance from 5,000 varieties in its collection, providing the raw material for marker-assisted breeding. “Once we knew which lines had the drought-tolerance and pest-resistance genes we were looking for, we crossed them with high-yielding lines to develop 20 advanced cowpea lines, which our African partners field tested,” says Phil.

The lines underwent final field tests in 2014, and the best-yielding drought-tolerant lines will be used locally in Burkina Faso, Mozambique and Senegal to develop new higher yielding varieties that will be available to growers by 2016.

“While we are still some time off from releasing these varieties, we already feel we are two or three years ahead of where we would be if we were doing things using only conventional breeding methods,” says Ndiaga.

Photo: IITA

A parasitic Striga plant, in a cowpea experimental plot.

The genome map and molecular markers have helped cowpea breeders like Ousmane Boukar, cowpea breeder and Kano Station Representative with the International Institute of Tropical Agriculture (IITA), headquartered in Nigeria, to locate the genes in cowpeas that play a role in expressing desirable traits.

Ousmane, who was GCP’s cowpea Product Delivery Coordinator, says, “We have used this technology to develop advanced breeding lines that are producing higher yields in drier conditions and displaying resistance to several pests and diseases like thrips and Striga. We expect these lines to be available to plant breeders by the end of 2015.

“TLI has had a huge impact in Africa in terms of developing capacity to carry out marker-assisted breeding,” he says. “This form of breeding helps us to breed new varieties in three to five years instead of seven to ten years.”

The Tropical Legumes I project (TLI) was initiated by GCP in 2007 and subsequently incorporated into the Programme’s Legumes Research Initiative (RI). The goal of the RI was to improve the productivity of four legumes – beans, chickpeas, cowpeas and groundnuts – that are important in food security and poverty reduction in developing countries, by providing solutions to overcome drought, poor soils, pests and diseases. TLI was led by GCP and focussed on Africa. Work on cowpea within TLI was coordinated by the University of California, Riverside in the USA. Target-country partners were Institut de l’Environnement et de Recherches Agricoles (INERA) in Burkina Faso, Universidade Eduardo Mondlane in Mozambique and Institut Sénégalais de Recherches Agricoles (ISRA; Senegalese Agricultural Research Institute) in Senegal. Other partners were the International Institute of Tropical Agriculture (IITA) and USA’s Feed the Future Innovation Labs for Collaborative Research on Grain Legumes and for Climate-Resilient Cowpea. Tropical Legumes II (TLII) was a sister project to TLI, led by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) on behalf of IITA and the International Centre for Tropical Agriculture (CIAT). It focussed on large-scale breeding, seed multiplication and distribution primarily in sub-Saharan Africa and South Asia, thus applying the ‘upstream’ research results from TLI and translating them into breeding materials for the ultimate benefit of resource-poor farmers. Many partners in TLI also worked on projects in TLII.

Burkina Faso – evaluating new lines to improve the country’s economy

Cowpea is an important crop for the people of Burkina Faso. Over 10 million farmers produce on average 800,000 tonnes of cowpeas each year, making the country the third largest producer in the world, behind neighbours Nigeria and Niger.

Much of Burkina Faso’s cowpea crop is consumed domestically, but the government sees potential in increasing productivity for export to Côte d’Ivoire and Ghana in the south. This new venture would improve the country’s gross domestic product (GDP), which is the third lowest in the world.

“The government is very interested in our research to improve cowpea yields and secure them against drought and disease,” says Issa Drabo, lead cowpea breeder with the Institut de l’Environnement et de Recherches Agricoles (INERA) in Burkina Faso.

“We’ve been working closely with UCR to evaluate advanced breeding lines that we can use in our own breeding programme. So far we have several promising lines, some of which breeders are using to create varieties for release to farmers – some as early as this year.”

Photo: IITA

Farmers in Burkina Faso discuss cowpea varieties during participatory varietal selection activities.

Outsourcing the molecular work

Issa says his team has mainly been using conventional breeding techniques and outsourcing the molecular breeding work to the UK and USA. “We send leaf samples to the UK to be genotyped by a private company [LGC Genomics], who then forward the data to UCR, who analyse it and tell us which plants contain the desired genes and would be suitable for crossing.”

The whole process takes four to six weeks, from taking the samples to making a decision on which plants to cross.

“This system works well for countries that don’t have the capacity or know-how to do the molecular work,” says Darshna Vyas, a plant genetics specialist with LGC Genomics. “Genotyping has advanced to a point where even larger labs around the world choose to outsource their genotyping work, as it is cheaper and quicker than if they were to equip their lab and do it themselves. We do hundreds of thousands of genotyping samples a day – day in, day out. It’s our business.”

Darshna says LGC Genomics have also developed plant kits, as a result of working more with GCP partners from developing countries. “We would receive plant tissue that was not properly packaged and had become mouldy on the journey. The plant kits help researchers package their tissue correctly. The genotyping data you get from undamaged tissue compared to damaged tissue is a thousand times better.”

Getting the genotyping expertise on the ground

Photo: IITA

A trader bagging cowpeas at Bodija market, Ibadan, Nigeria.

To reduce their African partners’ reliance on UCR, researchers from the university, including Phil, have been training young plant breeders and PhD students from collaborating institutes. Independent of the cowpea project, they have also been joining GCP’s Integrated Breeding Platform (IBP) training events in Africa to help breeders understand the new technologies.

“All this capacity building we do really gets at the issue of leaving expertise on the ground when the project ends,” says Phil. “If these breeders don’t have the expertise to use the modern breeding technologies, then we won’t make much progress.”

GCP Capacity Building Theme Leader and TLI Project Manager Ndeye Ndack Diop has been impressed by UCR’s enthusiasm to build capacity in its partner countries. “Capacity building is a core objective for GCP and the TLI project,” says Ndeye Ndack. “While it is built into almost all GCP projects, UCR have gone over and above what was expected of them and contributed towards building capacity not only among its partner institutions, but in many other African national breeding institutes as well.”

Issa Drabo reports that in 2014 two of his young researchers from Burkina Faso completed their training in GCP’s Integrated Breeding Multiyear Course, conducted by UCR and the IBP team.

One of Issa’s researchers at INERA, Jean-Baptiste de la Salle Tignegré, says the course helped him understand more about the background genetics, statistical analysis and data management involved in the process of molecular breeding. “Because of the course, we are now able to analyse the genotype data from LGC,” he says.

Mozambique – insects and drought are the problem

In 2010, the Universidade Eduardo Mondlane (UEM) joined the cowpea component of TLI, three years after the project started. “We were a little late to the party because we were busy setting up Mozambique’s first cowpea breeding programme, which only began in 2008,” recalls Rogerio Chiulele, a lecturer at the university’s Faculty of Agronomy and Forestry Engineering and lead scientist for cowpea research in Mozambique for TLI.

That year (2008), UEM received a GCP Capacity building à la carte grant to establish a cowpea-breeding programme for addressing some of the constraints limiting cowpea production and productivity, particularly drought, pests and diseases.

As in Burkina Faso and Senegal, in Mozambique cowpeas are an important source of food, for both protein and profit, particularly for the poor. Cowpeas rank as the fourth most cultivated crop in Mozambique, accounting for about nine percent of the total cultivated area, or an estimated four million hectares of smallholder farms.

Photo: IITA

Cowpea plants infested by aphids.

Rogerio says that farmers in his country, just as in other parts of Africa, struggle to reach their full yield potential because of climate, pests and diseases. “Several insect pests – such as aphids, flower thrips, nematodes and pod-sucking pests – can substantially reduce cowpea yield and productivity in Mozambique,” he says.

“Cowpea aphids can cause problems at any time in the growing season, but are most damaging during dry weather when they infest seedlings that are stressed from lack of water. In wetter parts of the country, flower thrips – which feed on floral buds – are the most damaging insect pest.” These insects are also major pests in Burkina Faso and Senegal, along with hairy caterpillar (Amsacta moloneyi), which can completely destroy swaths of cowpea seedlings.

Rogerio says breeding for insect resistance and drought tolerance, using marker-assisted techniques, improves breeders’ chances of increased cowpea productivity. “Productivity is key to increasing rural incomes, and new resources can then be invested in other activities that help boost total family income,” says Rogerio. “These new breeding techniques will help us achieve this quicker.”

Three high-yielding varieties to hit the Mozambique market in 2015

Photo: IITA

Mature cowpea pods ready for harvesting.

Since 2010, Rogerio’s team have quickly caught up to Burkina Faso and Senegal and plan to release three higher yielding new lines with drought tolerance in 2015. One of these lines, CB46, is based on a local cowpea variety crossed with a UCR-sourced American black-eyed pea variety that displays drought tolerance, which potentially has huge market appeal.

“Local varieties fetch, on average, half a US dollar per kilogram, compared to black-eyed pea varieties, whose price is in the region of four to five US dollars,” says Rogerio. “Obviously this is beneficial to the growers, but the benefits for consumers are just as appealing. The peas are better quality and tastier, and they take half as long to cook compared to local varieties.”

All these extra qualities are important to consider in any breeding programme and are a key objective of the Tropical Legume II (TLII) project (see box above). TLII activities, led by ICRISAT, seek to apply products from TLI to make an impact among farmers.

“TLII focuses on translating research outputs from TLI into tangible products, including new varieties,” says Ousmane Boukar, who works closely with Ndiaga, Issa and Rogerio in TLI and TLII.

Building a community of breeders to sustain success

Photo: C Peacock/IITA

Cowpea flower with developing pods.

Part of Ousmane’s GCP role as Product Delivery Coordinator for cowpeas was to lead a network of African cowpea and soybean breeders, and he champions the need for breeders to share information and materials as well as collaborating in other ways so as to sustain their breeding programmes post-GCP.

“To sustain integrated breeding practices post-2014, GCP has established Communities of Practice (CoP) that are discipline- and commodity-oriented,” says Ndeye Ndack. “The ultimate goal is to provide a platform for community problem solving, idea generation and information sharing.”

Ousmane says the core of this community was already alive and well before the CoP. “Ndiaga, Issa and I have over 80 years combined experience working on cowpea. We have continually crossed paths and have even been working together on other non-GCP projects over the past seven years.”

One such project the trio worked together on was to release a new drought-tolerant cowpea breeding line, IT97K-499-35, in Nigeria. “The performance of this variety impressed farmers in Mali, who named it jiffigui, which means ‘hope’,” says Ousmane. “We shared these new lines with our partners in Mali and Niger so they could conduct adaptation trials in their own countries.”

For young breeders like Rogerio, the CoP has provided an opportunity to meet and learn from these older partners. “I’ve really enjoyed our annual project meetings and feeling more a part of the world of cowpea breeding, particularly since we in Mozambique are isolated geographically from larger cowpea-producing countries in West Africa.”

For Phil Roberts, instances where more-established researchers mentor younger researchers in different countries give him hope that all the work UCR has done to install new breeding techniques will pay off. “Young researchers represent the future. If they can establish a foothold in breeding programmes in their national programmes, they can make an impact. Beyond having the know-how, it is vital to have the support of the national programme to develop modern breeding effort in cowpea – or any crop.”

Setting up breeders for the next 20 years

Photo: IITA

Farmer harvesting mature cowpea pods.

In Senegal, Ndiaga is hopeful that the work that the GCP project has accomplished has set up cowpea breeders in his country and others for the next 20 years.

“Both GCP’s and UCR’s commitment to build capacity in developing countries like Senegal cannot be valued less than the new higher yielding, drought-tolerant varieties that we are breeding,” says Ndiaga. “They have provided us with the tools and skills now to continue this research well into the future.

“We are close to releasing several new drought-tolerant and pest- and disease-resistant lines, which is our ultimate goal towards securing Senegal’s food and helping minimise the impact of the hungry period.”

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Jun 052015
 
Photo: Bill & Melinda Gates Foundation

Farmer Maria Mtele holds recently harvested orange-fleshed sweetpotatoes in a field in Mwasonge, Tanzania.

Sweetpotato has a long history as a lifesaver. The Japanese used it when typhoons demolished their rice fields. It kept millions from starvation in famine-plagued China in the early 1960s and came to the rescue in Uganda in the 1990s, when a virus ravaged the cassava crop.

In sub-Saharan Africa, sweetpotato is proving crucial in the fight against blindness, disease and premature death among children under five. And, as agriculture becomes more market-oriented across the continent, sweetpotato has some significant advantages: it requires fewer inputs and less labour than other crops such as maize, tolerates marginal growing areas and can mature within four months.

On these fertile grounds, researchers across the globe are not underestimating the importance of sweetpotato as a staple crop.

“Yields achieved by resource-poor farmers in sub-Saharan Africa are typically low,” says Roland Schafleitner of the International Potato Center (CIP), based in Peru.

“Improved and well-adapted sweetpotato varieties with increased tolerance to drought, pests and diseases will have a positive impact on food and income security in sub-Saharan Africa and can significantly contribute to increasing productivity,” he says.

Roland was Principal Investigator of two research projects funded by the CGIAR Generation Challenge Programme (GCP), which developed genetic and genomic resources for breeding improved sweetpotato.

At the outset of the work, Roland says: “Breeding efforts were limited by the crop’s genetic complexity and the lack of information available about its genetic resources.

“It was clear that if we could develop genetic tools and make concerted efforts towards understanding the gene pool of sweetpotato, the breeding potential of the crop would improve.”

Photo: Bill & Melinda Gates Foundation

Farmer Mwanaidi Rhamdani at work in an orange-fleshed sweetpotato field in Mwasonge, Tanzania.

Sub-Saharan Africans getting their vitamin A from sweetpotato

Photo: CIP

Sweetpotato diversity.

Malnutrition does not always mean a simple lack of calories; research suggests that nutrient shortfalls are an even bigger killer. Vitamin A deficiency is a leading cause of blindness, infectious disease and premature death among children under five and pregnant women in sub-Saharan Africa and Asia.

Sweetpotato comes in a wide range of colours. Varieties with dark orange flesh are naturally very rich in the pigment beta-carotene, which the body converts into vitamin A. However, the sweetpotatoes traditionally grown in Africa are pale-fleshed and low in beta-carotene. African consumers were not used to eating colourful sweetpotato – and these orange-fleshed varieties were in any case not well adapted African growing conditions.

Recent years have therefore seen a collaborative effort by researchers across the world to breed orange-fleshed sweetpotato varieties fortified with high levels of beta-carotene, and even enriched with other nutrients, that have also been crossed with local varieties and so are adapted to local conditions and tastes. A crucial part of these efforts has also been to create public awareness and encourage people to grow, eat and buy these new varieties.

Photo: HarvestPlus

Two cheeky young chappies from Mozambique enjoy the sweet taste of orange-fleshed sweetpotato rich in beta-carotene, or pro-vitamin A.

All of this adds to the growing momentum behind sweetpotato. The growing awareness of sweetpotato’s potential nutritional benefits for the poor and food insecure, as well as its value for subsistence farmers as a reliable crop that withstands drought and requires minimal inputs, mean that it is growing in significance.

Photo: HarvestPlus

Orange-fleshed sweetpotato can be used to make a variety of tasty products from doughnuts to chapati.

More than 95% of the world’s sweetpotato crop is grown in developing countries, where it is the fifth most important staple food crop. It is particularly important in many African countries: Madagascar in Southern Africa; Nigeria in West Africa; and those surrounding the Great Lakes in East and Central Africa – Uganda, Malawi, Angola and Mozambique.

According to 2013 figures from the Food and Agriculture Organization of the United Nations, 3.6 million hectares of sweetpotato were harvested in Africa. While the average global yield of sweetpotato per hectare was 14.8 tonnes, across all East African countries in 2013 it was only half this, at 7.1 tonnes per hectare. In West African nations the average yield was even worse, at 3.7 tonnes per hectare.

Farmers are unable to make the most of their crops because the varieties available to them, including traditional varieties (or landraces) have low resistance to viral diseases and insect pests, and poor tolerance to drought. It is therefore crucial that when developing new varieties breeders are able to efficiently incorporate pest and disease resistance and drought tolerance traits.

Sweetpotato, in spite of its name, is only distantly related to the potato. Unlike the potato – which is a tuber, or thickened stem – the sweetpotato is a root. Sweetpotato is not related to the yam either, despite the physical similarity between the two. Sweetpotato can grow at altitudes ranging from sea level to 2,500 metres. It requires fewer inputs and less labour than other crops such as maize, and, in contrast to the potato, it can tolerate heat.

New DNA markers identified for sweetpotato disease

The sweetpotato virus disease (SPVD) is the most serious disease affecting sweetpotato in sub-Saharan Africa. It often causes serious yield losses of up to 80–90 percent.

The disease is the result of joint infection by two viruses: the sweetpotato feathery mottle virus and the sweetpotato chlorotic stunt virus. Of the two, the stunt virus is the more problematic.

Wolfgang Grüneberg, also from CIP, says that, in the years 2006–2008, 52 new DNA markers were developed as part of GCP-funded research to improve marker-assisted selection for resistance to the disease.

“The results,” says Wolfgang, Principal Investigator for the research, “looked promising for developing a large number of orange-fleshed sweetpotatoes with resistance to SPVD.”

Immediately following the development of the markers, two varieties of sweetpotato were developed using a cloned gene, Resistan, known to confer resistance to the virus. The first variety was used to improve an SPVD test system so that the disease could be diagnosed earlier if a crop was affected. The second variety underwent field tests in regions in Uganda that were highly affected by the disease.

Photo: HarvestPlus

Sweetpotato vines and roots.

Mobilising the genetic diversity of sweetpotato for breeding

The goals of the GCP-supported work were to develop a diverse genetic resource base for sweetpotato and stimulate the use of new tools in ongoing breeding programmes.

To help transfer this work from high-end laboratories to resource-poor research labs in developing countries, GCP promoted collaboration across institutions and borders. Researchers from Brazil, Mozambique, Uganda and Uruguay worked together on sweetpotato genetic research projects.

As Roland explains, the basic first steps needed to begin to ‘mobilise’ the genetic diversity of sweetpotato were developing a reference set of varieties and improving genomics tools to work with polyploid crops, i.e. those possessing multiple sets of chromosomes, such as sweetpotato.

GCP-supported researchers in Peru and sub-Saharan Africa defined a reference set of 472 varieties of sweetpotato, carefully selected and honed to represent both the diversity of the crop and its most important agronomical and nutritional traits.

“Based on a reference set, genetic markers can be developed that are associated with important characteristics of the crop and can help breeders to select favourable genotypes,” says Roland.

The gene sequences developed during the Programme are now available as a Sweetpotato Gene Index.

“Based on these sequences,” says Roland, “molecular markers have been designed that can help breeders and gene-bank curators to assess the genetic diversity of their accessions and to perform genetic mapping studies.

“Today, techniques that yield a much larger number of markers for genetic studies and selection are accessible for sweetpotato,” he says.

Photo: Bill & Melinda Gates Foundation

Mwanaidi Rhamdani (left) works with Maria Mtele in an orange-fleshed sweetpotato field in rural Tanzania.

The genetic lifelines reach Africa

Sweetpotato is one of the most important staple crops in Mozambique, ranking in third position after cassava and maize. The areas harvested in Mozambique in 2013 were 1.7 million hectares of maize, 780,000 hectares of cassava and 120,000 hectares of sweetpotato.

Photo: CIP

A child eats cooked orange-fleshed sweetpotato in Uganda.

GCP funded breeders in Mozambique and Uganda to learn how to identify genetic markers that would prove useful for future sweetpotato breeding.

“Our African partners visited us at CIP and helped us complete the work on identifying markers,” recalls Roland. “This provided the opportunity for direct ‘technology transfer’ to breeders in the target region.”

The collaboration had, for the first time, created a critical amount of genetic and genomics resources for sweetpotato. The resulting Sweetpotato Gene Index and the new markers were published in a peer-reviewed journal, BMC Genomics (2010) 11:604.

The new genetic resources are in use at CIP in Peru and in breeding programmes in Burkina Faso, Mozambique, Uganda, Uruguay and the USA for the assessment of the genetic diversity of germplasm collections.

“The markers have been used for diversity analysis, especially at the CIP gene bank, and also in Africa,” says Roland, who says the markers will help future research.

“Such analysis guides germplasm conservation decisions, and diversity studies are a great tool to develop core collections and composite genotype sets – subsets of the whole collection – which allow for more practical screening for specific traits than large collections.”

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Photo: P Casier/CGIAR

Kenyan farmer Emily Marigu with her sweetpotatoes.

Jun 022015
 
Photo: S Edmeades/IFPRI

A farmer transports bananas to market by bicycle in Uganda.

At whatever time of the day or night you are reading this, somewhere in the world there are sure to be farmers trekking many kilometres to take their bananas to local markets. These small-scale farmers produce almost 90 percent of the world’s bananas, and make up a significant portion of the 400 million people around the globe’s tropical girdle – Africa, Asia and Latin America – who rely on bananas for food and a source of income.

Bananas are often called the world’s most popular fruit, and global production in 2012 was almost 140 million tonnes. India is the largest producer, while South and Central American farmers supply the most to international supermarket shelves, exporting 80 percent of their bananas.

The importance of the banana as a food crop in tropical areas cannot be underestimated. More than a simple snack, plantain-type bananas in particular are a key component in savoury dishes. In Central and East African countries – like Cameroon, Gabon, Rwanda and Uganda – one person will eat an average of between 100 kg and 250 kg of banana each year. That equates to somewhere between 800 and 2000 average-sized bananas. In those four countries, bananas account for up to a quarter of people’s daily calorie intake.

Photo:  A Vezina/Bioversity International

A stallholder offers bananas for sale at a fruit market in Nairobi, Kenya.

Banana’s asexuality inhibits its resilience

Photo: G Stansbury/IFPRI

Bananas growing in Rwanda.

Banana propagates though asexual reproduction. This means that all the bananas of each variety are genetically identical, or nearly so, and therefore susceptible to the same diseases. Indeed, the world has already lost almost its entire banana crop once: before the 1950s, the Gros Michel cultivar dominated banana exports, but it was gradually wiped out in most regions by Panama disease, caused by the fungus Fusarium oxysporum. Furthermore, with reproduction being asexual, it is difficult to develop new, resistant varieties through conventional breeding.

At the turn of the twenty-first century, pests and diseases were once again becoming a real threat to global banana production. Little genetic research had been done on the fruit, and only a small portion of its genes had been used in breeding new varieties in its 7,000-year history as a cultivated crop.

“Several research groups had developed genetic markers for bananas [‘flags’ on the genome that can be linked to physical traits], but there was no coordination and only sketchy germplasm studies,” recalls Jean Christophe Glaszmann from CIRAD (Centre de coopération internationale en recherche agronomique pour le développement; Agricultural Research for Development) in France.

Photo: N Palmer/CIAT.

A plantain farmer walks through a plantation in Quindió, Colombia.

“It was not a priority,” says Jean Christophe, who was Subprogramme Leader for Genetic Diversity for the CGIAR Generation Challenge Programme (GCP), an international initiative established in 2004 to encourage the use of genetic diversity and advanced plant science to improve crops.

But between 2004 and 2012, under GCP, a wealth of research work was undertaken that culminated in the complete genetic sequencing of banana. It was a long process, says Jean Christophe, but the GCP-funded work on banana made a significant contribution to important results.

The extensive data on the genetics of banana are now available to scientists worldwide, who can use it to delve deeper into banana’s genes to breed varieties that can sustain the poorer populations in developing countries.

Once finally sequenced, the banana genome was published in one of the most prestigious scientific journals, Nature, in July 2012: “The reference Musa [banana and plantains] genome sequence represents a major advance in the quest to unravel the complex genetics of this vital crop, whose breeding is particularly challenging. Having access to the entire Musa gene repertoire is a key to identifying genes responsible for important agronomic characters, such as fruit quality and pest resistance.”

Filling and full of fuel, and with the major advantage that it fruits year-round, the banana is vital to food security in the tropics. Bananas are potassium-rich and supply people in developing countries with a major source of carbohydrates. They also provide vitamin A, niacin, vitamin B6, thiamine, riboflavin and folic acid.

Passionate people pooled for the work

Photo: UN Women Asia & the Pacific

A banana seller in Hanoi, Vietnam.

Plans to sequence the banana genome started taking shape in 2001 at Bioversity International (a CGIAR centre), where a group of scientists formed the Global Musa Genomics Consortium. At that time, the only plant whose genome had been sequenced was Arabidopsis thaliana (a small flowering plant related to cabbage and mustard, used as a model organism in plant science), with rice close behind.

CGIAR established GCP in 2004 “to tap into the rich genetic diversity of crops via a global network of partnerships and breeding programmes,” according to Hei Leung, who was instrumental to GCP’s foundation and a Subprogramme Leader for Comparative Genomics. (During its first phase GCP was organised by Subprogramme; these were later replaced by Research Themes and Research Initiatives.)

Hei acknowledges that banana was ‘somewhat on the fringe’ of GCP’s main focus on improving drought tolerance in crops. However, he says, it was still relevant for GCP to support the emergence of improved genetics for banana.

The work we did in genetic diversity is about future generations. We wanted a programme that is pro-poor, meaning that the majority of the people in the world are depending on [the crop].

Photo: Adebayo/IITA

A typical banana and plantain market at Ikire in Osun State, Nigeria.

“Drought tolerance is a good candidate because drought affects a lot of poor areas, but you really cannot just take one trait as pro-poor. We had a highly motivated group of researchers willing to devote their efforts to Musa,” says Hei.

“Nicolas Roux at Bioversity International was a passionate advocate for the partnership,” notes Hei. “The GCP community offered a framework for novel interactions among banana-related actors and players working on other crops, such as rice.”

Nicolas concurs on the potential for a little banana research to have great value: “Even though banana is among the most important basic food crops for 400 million people, and 100 million tonnes are grown annually on over 10 million hectares in 120 countries, it’s still under-researched and underfunded.”

The resultant research team was led by Japan’s National Institute of Agrobiological Sciences, which had vast experience in rice genome sequencing.

“So, living up to its name as a Challenge Programme, GCP decided to take the gamble on banana genomics and help it fly,” says Hei.

To advance genetics, you first need the intelligence

Photo: IITA

Banana bunches on an experimental plot at IITA.

Three global research agencies were charged with working together to develop a reference set for banana: Bioversity International, CIRAD, and the International Institute of Tropical Agriculture (IITA).

Creating a reference set – a careful, tactical selection representing the genetic diversity of a crop – is an invaluable first step in enabling scientists to work together to develop more ‘intelligent’ genetic data.

“Initially, we put together a community of institutions that have collections [of banana germplasm],” explains Jean Christophe. “And then we put together these initial materials that we sample in order to develop representative subsamples – this is called a ‘composite’ set because it comes from different institutions.

“Then we genotype this composite collection, and the genotyping allows us to understand how all this [genetic material] is structured. Based on how it is structured, we can re sample a smaller representation – this is what becomes a reference set.”

So, in the case of crops with an extensive genetic resource base, such as rice, there may be more than 100,000 different plant samples, or accessions, that are reduced to a few thousand. For banana, which has a smaller genetic resource base, a few hundred thousand accessions can be reduced to a few dozen.

“A couple of hundred accessions or fewer become manageable for plant breeders or crop specialists. And we want this to serve as a reference, shared among people, so that everybody works on the same reference material,” says Jean Christophe.

“If you work on the same reference material, you can compile information that is more intelligent – you can have the crop specialist who says ‘this is resistant; this is tolerant; this is susceptible’, and you can also have the biochemist, you can have the physiologist; in the end, you can compile the information.”

“We analysed about 500 accessions and narrowed it down to 50,” says Jean Christophe. This reference collection is currently stored at the University of Leuven in Belgium.

The refined data collected on the banana reference set enabled the researchers to unravel the origin and genealogy of the most important dessert banana: the Cavendish, the cultivar subgroup that dominates banana exports worldwide. Thanks to the early GCP work, they were able to show that Cavendish bananas evolved from three markedly different subspecies.

Photo: C Sokunthea/World Bank

65-year-old Cambodian farmer, Khout Sorn, stands in front of his banana trees in Aphiwat Village, Tipo commune, Cambodia.

Malaysian wild subspecies fully sequenced

During these preliminary years of GCP-supported research on banana, the Programme funded several other smaller projects to consolidate genomic resources available for banana. Scientists developed libraries of artificial chromosomes that can be used in sequencing the DNA of banana, as well as genetic maps, which according to Jean Christophe are essential for improving the quality of the sequence.

These projects contributed to the full genome sequencing of a wild banana from Malaysia’s Pahang province in 2008. The ‘Pahang’ subspecies is one of the Cavendish variety’s three ancestors, and has also been shown to have had a role in the origin of many other banana cultivars, including those that are most important for food and economic security.

“GCP did not fund the sequence [of the Pahang banana], but it funded several things that made it possible to undertake full-scale sequencing,” Jean Christophe says. “It supported the development of particular resources and tools, and this made it possible for researchers to start the full-length sequencing.”

Photo: Asian Development Bank

A farmer at work on a banana plantation, Mindanao, the Philippines.

Breeders now need to set to work

The more that is known about the genes responsible for disease resistance and other desirable traits in banana, the more researchers will be able to help farmers in developing countries to improve their yields.

“The road remains long, but now we have a good understanding of genetic diversity,” says Jean Christophe. “We have done a range of studies aimed at unravelling the genes that could control sterility in the species.

“This is undoubtedly an inspiring challenge towards unlocking the genetic diversity in this crop.

“If we have more money in the future, we are going to sequence others of the subspecies so that we can have the full coverage of the current Cavendish genome. But that was a good start,” says Jean Christophe.

“What we have to do now is to create the right populations [of banana] in the field so that we can separate out the characteristics we want to breed for.”

The new intelligence on banana genetics has given breeders the material they need that will ultimately help 400 million people in the tropics sustain food supplies and livelihoods.

More links

Photo: N Palmer/CIAT

Bananas on the way to market in Kenya.

Mar 262015
 

 

Photo: R Cheung/Flickr

Wheat growing in China.

For as long as peoples and countries have traded wheat, drought has continually played a part in dictating its availability and price. Developed countries have become more able to accommodate the bad years by using intensive agricultural practices to grow and store more wheat during more favourable years. However, farmers, traders and consumers are still at the mercy of drought when it comes to wheat availability and prices.

A recent example where drought in just one country inflated the world’s wheat prices was in the People’s Republic of China during 2010–11.

For almost six months, eight provinces in the north of China received little to no rain. Known as the breadbasket of China, these eight provinces grow more than 80 percent of the country’s total wheat and collectively produce more wheat than anywhere else in the world.

It was the worst drought to hit the provinces in 60 years.

With over 1.3 billion mouths to feed, China’s demand for wheat is high and ever increasing. When this demand was coupled with the reduced wheat yield caused by the severe 2010–11 drought, wheat prices around the world rose. While this price rise was beneficial for wheat growers in other countries, it made wheat unaffordable for many consumers and traders in developing nations.

Although this was a one-in-60-year event, previous droughts had already made locals question the sustainability of wheat production in this naturally dry region of China, where water consumption has increased in the past 50 years due to intensive agriculture, industry and a growing and increasingly urbanised population.

Wheat growers and breeders know they need to find wheat varieties and apply practices that will help them adapt to and tolerate drier conditions and still produce sustainable yields.

Luckily, they have help from a community of breeders around the world.

Photo: E Zotov/Flickr

An Uyghur baker displays his bread in Kashi, Xinjiang, China.

Sharing knowledge to improve breeding efficiency and sustainability

In March 2009, 70 international plant breeding leaders and experts from the public and private sector converged in Montpellier, France, as part of a CGIAR Generation Challenge Programme (GCP) initiative to draw up roadmaps to improve plant-breeding efficiency in developing countries.

Richard Trethowan, professor in plant breeding at the University of Sydney, Australia, remembers the meeting distinctly. “We all got together and thought how we could use what we had learnt during the first phase of GCP [2004–2009] – all the genetics and molecular-breeding work – to deliver new varieties of crops, particularly in countries where it will have the greatest impact.”

The resulting roadmap for wheat became the GCP Wheat Research Initiative (RI), with Richard as Product Delivery Coordinator. It had two very clear destinations in mind: China and India.

Richard explains why China and India were targeted – as the world’s two wheat-production giants – in the video below.


Wheat Research Initiative developed capacity and infrastructure in China and India The Wheat RI aimed to integrate genetic diversity for water-use efficiency and heat tolerance into Chinese and Indian breeding programmes. Some aspects of the RI sprang from work led by Francis Ogbonnaya of the International Center for Agricultural Research in the Dry Areas (ICARDA) and by Peter Langridge of the Australian Centre for Plant Functional Genomics (ACPFG). Jean-Marcel Ribaut, GCP Director, says of the work: “The GCP’s RI approach was not about large impacts in the short term. Rather, what GCP demonstrated was definitive proof-of-concept of the power of molecular breeding to increase crop productivity, thereby improving food security. Other agencies are now able to upscale and outscale the proven concept at the national, or even at the regional level.”

Like China, India is an extremely water-stressed country, with the water table in many places falling at an alarming rate. In North Gujarat alone, an established wheat district in western India, the water table is reported to be dropping by as much as six metres per year.

Delivering wheat varieties that have improved water-use efficiency and higher tolerance to drought will have the greatest impact in these countries, given they are the two largest producers of wheat worldwide.

“Even though the Initiative is set to conclude in 2015, the outcomes have already been absolutely phenomenal for such a short time-bound project, given that wheat is such a complex plant to work with,” exclaims Richard. “While we are still a few years away from releasing new drought-tolerant varieties, we have been able to develop systems and build capacity to reduce the time it takes to develop and release these varieties.”

Tapping into genetic diversity to enhance wheat’s drought and heat tolerance

Photo: Rasbak/Wikimedia Commons

Spikes of emmer wheat.

One project that impressed Richard was that led by Satish Misra, GCP Principal Investigator and senior wheat breeder at Agharkar Research Institute, Pune, India.

In a collaboration with the University of Sydney, Australia, and the International Maize and Wheat Improvement Center (CIMMYT), the project identified novel genes associated with drought- and heat-tolerance traits in ancestral wheat lines (of emmer wheat).

Emmer wheat is a minor crop grown mainly in marginal lands, where farmers can produce a small harvest but nowhere near the yield of more elite cultivated lines. Satish explains that emmer wheat lines are very useful for breeders because they have a larger diversity of novel genes than more popular wheat types, such as durum or bread wheat.

Photo: X Fonseca/CIMMYT

Durum wheat spike.

“Durum lines are more commonly used by breeders because of their high yield and hard grain, which is used to make bread wheat and pasta,” Satish says. “However, because of their popularity and continual use in breeding, durum wheat lines have become less and less diverse with years of cultivation.”

The first task was to identify emmer lines that might have genes for drought and heat tolerance. Satish says that CIMMYT played an important part in this process. “They gave us access to their gene bank, which contains almost 2,000 emmer lines. More importantly, they helped us develop a reference set that encapsulated all the diversity found in the emmer lines they had.”

A reference set reduces the number of choices that breeders have to search through, from thousands down to a few hundred – in this case, 300 emmer lines.

“CIMMYT also developed 30 synthetic emmer wheat lines by crossing wild emmer wheat species with domesticated wheat species,” says Satish. “The synthetic lines contain the novel drought- and heat-tolerance genes.”

Satish and Richard’s teams crossed these synthetic lines with durum wheat lines and identified 41 resulting lines with high levels of stress tolerance. These are undergoing further evaluation in India and Australia.

“What Satish has been able to do in five years is amazing and is currently having a big impact in wheat breeding in India and Australia,” says Richard. “We’ve had local breeding companies here in Australia come to us requesting the lines we developed. The same is happening in India, too.”

Reaping existing skills  For Richard, the preliminary success of the Wheat RI is due, at least in part, to the speed with which national breeding programmes in both China and India are learning and incorporating new molecular-breeding techniques. “This was another reason why we chose to focus on China and India: they had the infrastructure and human capacity to start doing this almost immediately,” says Richard. “In other countries where GCP is investing, more time is going into teaching breeders the basics of molecular breeding and genetics. In China and India, they already have that basic understanding and are able to quickly incorporate it into their current programmes.”

Reaping existing skills

Photo: R Pamnani/Flickr

A baker butters naan bread in Hyderabad, India.

For Richard, the preliminary success of the Wheat RI is due, at least in part, to the speed with which national breeding programmes in both China and India are learning and incorporating new molecular-breeding techniques.

“This was another reason why we chose to focus on China and India: they had the infrastructure and human capacity to start doing this almost immediately,” says Richard. “In other countries where GCP is investing, more time is going into teaching breeders the basics of molecular breeding and genetics. In China and India, they already have that basic understanding and are able to quickly incorporate it into their current programmes.”

This does not mean, however, that the work is not focused on building capacity, given that molecular breeding is still a relatively new concept for many breeders around the world.

Ruilian Jing says the China project is continually working to educate and train wheat breeders in molecular-breeding techniques.

“When we started the project, we found that most institutions that focus on wheat breeding in China had the equipment to do marker-assisted breeding but were unsure how to use it,” says Ruilian, professor in plant breeding at the Chinese Academy of Agricultural Sciences (CAAS) and Principal Investigator for the Wheat RI’s drought-tolerant wheat project in China.

Much of Ruilian’s work in China has been in educating these breeders so they can start achieving outcomes.

Younger researchers taking a lead

Ruilian explains that those leading the charge to become educated in molecular-breeding techniques are young researchers, including seven PhD students and one Master’s student supported by the project in China.

One such researcher who is enthusiastically applying these new approaches is Yonggui Xiao, a molecular plant breeder at the Institute of Crop Science, CAAS.

“Working as part of this GCP project gave me my first opportunity to practice using molecular-breeding techniques to improve the quality and yield of wheat under drought conditions,” says Yonggui.

“We have so far successfully used several molecular markers to produce an advanced variety, with higher yield and preferred qualities [taste, grain colour] under water stress, and this will be released to farmers [in 2015].”

Photo: R Saltori/Flickr

Women of the Nakhi people harvest wheat in Songzanlinsi, Yunnan, China.

Yonggui is now expanding the application of the technology to develop varieties with resistance to powdery mildew, a fungal disease that can reduce wheat yields and quality during non-drought years. “Overall, we have been impressed by how these new techniques complement our conventional breeding techniques to improve selection efficiency, in turn reducing the time and costs of producing advanced varieties,” says Yonggui.

Success stories like these make Ruilian’s job easier as she tries to encourage more and more plant breeders to experiment with these new breeding techniques.

At the same time, she is impressed by this new generation of molecular wheat breeders who will ensure that these techniques benefit wheat research in many years to come: “This form of capacity, the human capacity, which we are building, is what will leave the largest legacy in China and help this technology spread from generation to generation and crop to crop.”

Overcoming complex traits, genes and wary breeders

Photo: CCAFS

Wheat farmer in India.

Across the Himalayas, Ruilian’s Indian counterpart, Vinod Prabhu, is just as pleased with the progress and results his team are producing.

“Over the last five years, we have discovered several water-use efficiency traits and their related genes, bred new lines to incorporate the genes and traits and run national trials, all of which would be unheard of using only conventional breeding practices,” says Vinod, Head of the Genetics Division at the Indian Agricultural Research Institute in New Delhi and the Principal Investigator for the Wheat RI’s drought-tolerant wheat project in India.

By the end of the projects in November 2015, partners in China and India will deliver 15–20 new wheat lines with drought and heat tolerance, adapted to each country’s conditions. An additional target for both China and India is to produce four wheat varieties with improved water-use efficiency and higher heat tolerance. These varieties will have the potential to cover about 24 million hectares and minimise yield loss from heat or drought, or both, by up to 20–50 percent.

Vinod confides that all these outcomes are far more than what he initially expected they would achieve: “When we started, we had a lot of reservations about the complexity of breeding for drought tolerance in wheat as well as the acceptance and uptake of these new breeding techniques by conventional breeders.”

Vinod’s primary role has been to coordinate the Indian centres working on the project (see box at end). But he has also been working to convince Indian plant breeders that these unconventional, new breeding techniques will improve their efficiency and aid in their quest to breed for heat- and drought-tolerant wheat varieties.

“Many world-leading wheat breeders were wary at first, but they have definitely started to see the merit in using the technology to enhance their conventional methods as we edge closer towards releasing new varieties in such a short time,” says Vinod.

Photo: N Palmer/CIAT

Wheat seed ready for planting in Punjab, India.

Incorporating conventional methods

An aspect of the Wheat RI that Ruilian and Vinod have been continually promoting is the importance of conventional breeding methods. “These new molecular-breeding techniques are only a small part of the whole breeding process,” says Ruilian. “Yes, they provide a big impact, but in the grand scheme of things they need to be viewed as one tool in a breeder’s tool box.”

Conventional vs marker-assisted breeding To conventionally breed a new wheat variety, two wheat plants are sexually crossed. The aim is to combine the favourable traits from both parent plants and exclude their unwanted traits in a new and better plant variety. This is achieved by selecting the best plants from among the progeny over several generations. Marker-assisted breeding allows breeders to be much more efficient and targeted in their activities. It still requires breeders to sexually cross plants, but they can use genetic information to tell them which plants have particular genes for useful traits, which helps them to choose which parent plants to cross, and then to confirm which of the progeny have inherited the desired gene without necessarily growing and phenotyping all of them under conditions that would express that trait.

For more information on conventional versus molecular breeding, or marker-assisted breeding, see our quick guide here on the Sunset Blog.

Phenotyping: How to manage a subjective process

One of the most important processes of the Wheat RI, and plant breeding in general, is phenotyping: measuring and recording observable characteristics of the plant such as drought tolerance or susceptibility to pests and diseases. Breeders phenotype the plants they have developed to see which ones have the traits they are interested in and also – for molecular breeding to be possible – to establish links between specific genes and specific traits.

Unfortunately, phenotyping has caused a bit of trouble for both Chinese and Indian partners. The challenge stems from the fact that one person’s observations about a plant’s phenotype or characteristics may not be the same as another person’s.

“This is always a challenge for any collaborative plant-breeding project,” says Vinod. “Unless all trials are inspected by one person, there will always be a risk of inconsistent observations.

Photo: CIMMYT

Scientists from South Asia learn phenotyping on a training course at CIMMYT.

To help overcome this inconsistency, one of the first activities of the Wheat RI was to develop phenotyping protocols that allowed researchers in different research institutes and countries to collect comparable data. GCP enlisted Matthew Reynolds, a wheat physiologist at CIMMYT, to help with this.

“Each breeder has their own ways to do things, so it’s important to develop standardised protocols, particularly for a transnational project like this,” explains Matthew. “We developed a few standardised phenotyping manuals and travelled to China to give some intensive hands-on training.”

This problem is not unique to China and India. Another GCP wheat project is providing promising results to help overcome the risk of inconsistency and increase the efficiency and accuracy of phenotyping. Led by Fernanda Dreccer, based at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), in collaboration with the International Center for Agricultural Research in the Dry Areas (ICARDA), the project is developing a reliable phenotyping approach to detect drought-adaptive traits in wheat crops using cheap and simple tools.

“For example, using just a camera you can analyse crop cover, which is an important trait for shading the crop and/or trapping heat,” says Fernanda. “The idea was to test different non-invasive, low-cost tools and compare them to find something that would provide accurate and useful data related to identifying drought-tolerance traits.”

Another important aspect of phenotyping that Fernanda’s project is helping with is constant and consistent analysis of a crop’s surroundings. “It’s just as important to measure the environment of the crop as it is [to measure] the crop itself to make a correlation between an environmental impact and a plant’s reaction,” says Fernanda.

Since the static nature of single observations can give a misleading or incomplete picture, Fernanda’s team is integrating live crop, weather and soil data through mobile sensors in the field with the aim of producing constant phenotypic information. “This will provide new insights into the interaction between the genotype and the environment. This in turn will help to accelerate the detection of wheat genotypes better suited to cope with drought.”

Photo: R Martin/CIMMYT

A young farmer in her wheat field in India.

Managing the tsunami of phenotyping data

Although a plant breeder’s work should be simplified and made more efficient by combining molecular-breeding technologies with advanced phenotyping techniques and protocols, the reality is not necessarily so easy.

There are many steps to the plant-breeding puzzle, all of which produce data. The more advanced the techniques and – in the case of wheat – the more complex the plant’s genome, the more pieces of data breeders need to sift through to find solutions.

Before the Wheat RI started, Richard saw that this impending tsunami of data was going to be a problem in both China and India: “Both countries had the skills to carry out these advanced techniques, but they didn’t have in place a strong culture of data management.”

This problem is by no means unique to China and India, Richard says: “Most of the time, plant breeders keep a log of all their data in a book or Excel sheet. However, these data often get lost once a project is completed.”

GCP recognised this problem before the RIs began and has, since 2009, been developing the Breeding Management System (BMS) – a suite of interconnected software designed to manage the mass of data – as part of its Integrated Breeding Platform (IBP).

“The BMS is the first tool that can help breeders record and collate their data in a coordinated way,” says Richard. “This is vital in a project like this, which has several institutes across three countries working towards a similar product.”

Vinod agrees with Richard, adding that the BMS was relatively easy for his Indian partners to learn and use: “The BMS is great as we have no way of losing data.”

Rolling out the BMS in China, though, has been more difficult due to the language barrier. Ruilian explains: “We are now working towards translating the IBP, but it will be an ongoing challenge as the platform continually changes and is updated.”

Ruilian is optimistic that a translated BMS will become a viable tool for Chinese breeders in the future. “The more that we collaborate with other countries, the more a tool like this becomes important to have.”

Watch Richard on adoption of IBP tools in the video below.

Friendly competition helping inspire India’s wheat breeders

Vinod credits two things for the successful development of new wheat varieties and integration of new breeding techniques and data-management systems: a clear, logical plan and friendly competition between China and India to breed the first new drought-tolerant varieties.

“The initial plan, which Richard helped develop in Montpellier, was logical and well thought out. Although we initially thought it was overambitious in its objectives, we have been able to meet them so far, which is a great credit to the team and their enthusiasm to try these new technologies and see for themselves the benefits first hand.

“What has also helped is our competitive spirit, as we would like to achieve the objectives before the Chinese breeders do. Our breeders are always asking me for updates on how China is progressing!” Vinod adds, with a chuckle.

Ruilian agrees with Vinod’s assessment, adding: “The project would not have been as successful if it was solely national. It needed the international collaboration and friendly competition to help build confidence and drive.”

For Richard this international collaboration, between two very different and proud cultures, allowed the project to broaden its scope and troubleshoot quicker than usual.

“They [the Chinese and Indian researchers] think about problems in different ways. When you get a group of people in a room from different backgrounds, you can come up with great integrated plans, things you would never have come up with within just a national team,” says Richard.

Watch Richard on the beauty of diversity in research partnerships in the video below.

Securing wheat production into the future

With the project concluding in 2015, both the Chinese and Indian researchers are working towards completing national trials and releasing their new, advanced drought-tolerant varieties to farmers and other breeders. However, for Richard, the impact of the Wheat RI may not be fully recognised for 10–20 years.

“The initial new varieties that both China and India develop will help farmers in the short term. However, as both countries become more advanced in using the technology, future varieties are sure to be more and more robust. What’s more, these techniques and tools are sure to filter through to other national wheat-breeding programmes, as well as to other crops.”

In the case of wheat, new drought-tolerant varieties will help secure both China’s and India’s wheat industries, helping to stabilise wheat yields, and consequently prices, the world over. These new varieties may not be the silver bullet for eliminating the risks of drought, but they will go a long way to mitigating its impact.

Photo: Rosino/Flickr

Donkeys bring home the wheat harvest in Qinghai, China.

The GCP Wheat Research Initiative involved 10 institutes from China, India and Australia: China – Chinese Academy of Agricultural Sciences (Institute of Crop Science; National Key Facility for Crop Gene Resources and Genetic Improvement) Hebei Academy of Agricultural Sciences Shanxi Academy of Agricultural Sciences  Xinjiang Academy of Agricultural Sciences India – Indian Agricultural Research Institute Punjab Agricultural University Agharkar Research Institute  National Research Centre on Plant Biotechnology Jawaharlal Nehru Krishi Vishwa Vidyalaya Australia – Plant Breeding Institute, University of Sydney The Wheat RI built on several previous GCP projects conducted by the International Maize and Wheat Improvement Center (CIMMYT) and International Center for Agricultural Research in the Dry Areas (ICARDA).

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Mar 192015
 
Photo: N Palmer/CIAT

A farmer harvests her pearl millet crop in Ghana’s Upper West Region.

Pearl millet is the only cereal crop that can be grown in some of the hottest and driest regions of Asia and Africa. It is a staple provider of food, nutrition and income for millions of resource-poor people living on these harsh agricultural lands.

Even though pearl millet is well adapted to growing in areas characterised by drought, poor soil fertility and high temperatures, “there are limited genetic tools available for this orphan crop,” reported researcher Tom Hash at the International Crop Science Congress 10 years ago.

“The people who relied on this crop in such extreme environments had not benefitted from the ‘biotechnology revolution’, or even the ‘green revolution’ that dramatically increased food grain production on irrigated lands over a generation ago,” adds Tom, now Principal Scientist (Millet Breeding) in the Dryland Cereals Research Program of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). This lack of research dividends was despite the fact that pearl millet is the sixth most important cereal crop globally.

It was at this time – in 2005 – that the CGIAR Generation Challenge Programme (GCP) stepped up to invest in more genetic research for pearl millet (along with finger and foxtail millet).

Photo: S Mann/ILRI

Newly harvested pearl millet heads in Niger.

The use of genetic technologies to improve pearl millet had already made some advances through work carried out in the United Kingdom. The GCP initiative was established to improve food security in developing countries by expanding such available genetic work to create crops bred to tolerate drought, disease and poor soils.

With financial support from GCP, and with the benefit of lessons learnt from parallel GCP genetic research, ICRISAT scientists were able to develop more advanced tools for breeding pearl millet.

Pearl millet is used for food for humans and animals and is an essential component of dryland crop-livestock production systems like those of the Sahel region of Africa. It is a main staple (along with sorghum) in Burkina Faso, Chad, Eritrea, Mali, Niger, northern Nigeria, Senegal and Sudan. It has the highest protein content of any cereal, up to 22 percent, and a protein digestibility of about 95 percent, which makes it a far better source of protein than other crops such as sorghum and maize. Pearl millet grain is also a crucial source of iron and zinc. Pearl millet is the most widely grown millet (a general term for grain harvested from small-seeded grasses), and accounts for approximately 50 percent of the total world millet production. It has been grown in Africa and South Asia, particularly in India, since prehistoric times and was first domesticated in West Africa. It is the millet of choice in hot, dry regions of Asia, Africa and the Americas because it is well adapted to growing in areas characterised by drought, poor soil fertility and high temperatures; it even performs well in soils with high salinity or low levels of phosphorous. In short, thanks to its tolerance to harsh environments, it can be grown in areas where other cereals such as maize or wheat do not survive or do not yield well.

Protein in pearl millet ‘critical’ for nutrition

Photo: P Casier/ICRISAT HOPE

A farmer harvests millet in Mali.

Mark Laing, Director of the African Centre for Crop Improvement (ACCI) at the University of KwaZulu-Natal in South Africa, says the GCP-supported work on pearl millet will have long-term impacts.

He says it is the high protein content of pearl millet that makes it such a crucial crop for developing countries – in Africa, this is the reason people use pearl millet for weaning babies.

“It was interesting to us that African people have used pearl millet as a weaning food for millennia. The reason why was not clear to us until we assessed the protein content,” says Mark. “Its seed has 13–22 percent protein, remarkable for a cereal crop, whereas maize has only eight percent protein, and sorghum has only two percent digestible protein.”

Photo: S Kilungu/CCAFS

Pearl millet growing in Kenya.

Tom Hash agrees, adding: “More importantly, pearl millet grain has much higher levels of the critically important mineral micronutrients iron and zinc, which are important for neurological and immune system development.

“These mineral micronutrients, although not present in a highly available form, can improve blood iron levels when used in traditional pearl millet-based foods. Pearl millet grain, when fed to poultry, can provide a potentially important source of omega-3 fatty acids, which are also essential for normal neurological development.”

Pearl millet endowed with genetic potential

Photo: AS Rao/ICRISAT

A farmer with his pearl millet harvest in India.

In a treasure-trove of plant genetic resources, thousands of samples, or accessions, of pearl millet and its wild relatives are kept at ICRISAT’s gene banks in India and Niger.

For pearl millet alone, in 2004 ICRISAT had 21,594 types of germplasm in its vaults at its headquarters in India. This represents a huge reservoir of genetic diversity that can be mined for data and for genetic traits that can be used to improve pearl millet and other crops.

Between 2005 and 2007, with support from GCP, scientists from ICRISAT set to work to do just that, mining these resources for qualities based on observed traits, geographical origin and taxonomy.

Hari D Upadhyaya, Principal Scientist and Director of Genebank at ICRISAT, led the task of developing and genotyping a ‘composite collection’ of pearl millet. To do this, the team created a selection that reduced 21,594 accessions down to 1,021. This collection includes lines that are tolerant to drought, heat and soil salinity; others resistant to blast, downy mildew, ergot, rust and smut; and accessions resistant to multiple diseases.

Photo: C Bonham/Bioversity International

A traditional pearl millet variety growing in India.

The collection also includes types of pearl millet with high seed iron and zinc content (from traditional farmer varieties, or landraces, from Benin, Burkina Faso, Ghana and Togo), high seed protein content, high stalk sugar content, and other known elite breeding varieties.

The final collection comprised 710 landraces, 251 advanced breeding lines, and 60 accessions from seven wild species.

The GCP-supported scientists then used molecular markers to fingerprint the DNA of plants grown from the collection. Molecular markers are known variations in the sequence of the genetic code, found in different versions within a species, which act as flags in the genome sequence. Some individual markers may be associated with particular useful genes, but markers are useful even without known associations, as the different flags can be compared between samples. In the pearl millet research, scientists searched for similarities and differences among these DNA markers to assess how closely or distantly related the 1,021 accessions were to each other.

This was not only a big step forward for the body of scientific knowledge on pearl millet, but also for the knowledge and skills of the scientists involved. “The GCP work did make some significant contributions to pearl millet research,” says Tom, “mainly by helping a critical mass of scientists working on pearl millet to learn how to appropriately use the genetic tools that have been developed in better-studied fungi, plants and animals (including people).”

GCP extends know-how to Africa

Photos: N Palmer/CIAT

Comparisons of good and bad pearl millet yields in Ghana’s Upper West Region, which has suffered failed rains and rising temperatures.

The semiarid areas of northern and eastern Uganda are home to a rich history and culture, but they are difficult environments for successful food production and security.

In this region, pearl millet is grown for both commercial and local consumption. Its yields, although below the global average, are reasonable given that it is grown on poor sandy soils where other crops fail. Yet despite being a survivor in these harsh drylands, pearl millet can still be affected by severe drought and disease.

GCP helped kick-start work to tackle these problems. With financial support from GCP, and through ACCI, Geofrey Lubade, a scientist from Uganda, was able to study and explore breeding pearl millet that would be suitable for northern Uganda and have higher yields, drought tolerance and rust resistance.

Geofrey now plans to develop the best of his pearl millet lines for registration and release in Uganda, which he expects will go a long way in helping the resource-poor.

But Geofrey’s success is just one example of the benefits from GCP-support. Thanks to GCP, Mark Laing says that his students at ACCI have learnt invaluable skills that save significant time and money in the plant-breeding process.

“Many of our students, with GCP support, have been involved in diversity studies to select for desirable traits,” says Mark – and these students are now working on releasing new crop varieties.

He says that African scientists directly benefitted from the GCP grants for training in biotechnology and genetic studies.

Their work, along with that of a number of other scientists, will have a huge impact on plant breeding in developing countries – long term.

Photo: N Palmer/CIAT

A farmer inspects his millet crop in northwest Ghana.

As Mark explains, once breeders have built up a head of steam there is no stopping them. “Plant breeders take time to start releasing varieties, but once they get started, then they can keep generating new varieties every year for many years,” he says. “And a good variety can have a very long life, even more than 50 years.

“We have already had a significant impact on plant breeding in some African countries,” says Mark. But perhaps more importantly, he says, the work has changed the status of plant breeding and pearl millets as a subject: “It used to be disregarded, but now it is taken seriously as a way to have an impact on agriculture.”

For research and breeding products, see the GCP Product Catalogue and search for pearl millet.

Mar 172015
 

 

Photo: IRRI

Harvesting rice by hand in The Philippines.

Rice plays a key role in global food security, particularly in Asia, where 90 percent of the world’s rice is grown and eaten. By 2050, Asia’s population is estimated to grow by one billion to 5.2 billion people, who will continue to depend on rice as their major staple food.

But with rising demand for rice has also come increasing salinity, droughts and other stresses, along with decreasing areas of land available for farming the crop.

And that’s why the CGIAR Generation Challenge Programme (GCP) placed a major focus on rice throughout its 10 years of existence.

Key ingredient in the rice research fest was GCP’s relationship with the International Rice Research Institute (IRRI), headquartered in The Philippines. GCP supported IRRI in its endeavours to use the latest molecular plant-breeding techniques, along with traditional plant-breeding tools, to develop rice crops better able to cope with various stresses and still be productive.

“These ‘super’ crops will revolutionise rice farming,” says IRRI Director General Robert Zeigler, who was also the first Director of GCP.

For more on GCP’s rice research see our Sunset Story ‘The power of rice unlocked’.

Rice that can survive increasingly salty water

Climate change is one of the major threats facing rice production. As sea levels rise, salt water enters further up rivers with the high tides and affects rice production areas.

Each year in Bangladesh, during the boro rice season from November to May, salinity is so high that a white film of salt covers the country’s coastal paddy fields. For Bangladeshi farmers, this white colour is a warning sign that their land is ‘sick’. Around the world, Bangladesh, India, Myanmar and parts of Africa are most affected by increasing salinity.

Right from the beginning of GCP, salinity was a problem firmly on the rice research agenda.

Photos: IRRI

Highly saline soils in India (left), and a close-up showing a surface crust of salt on afflicted soil (right).

Leading this research was IRRI plant physiologist Abdelbagi Ismail, who dreamed of the ‘super’ rice crop that could “tolerate salinity, drought and submergence”.

Abdelbagi has managed and overseen most of the progress made during the discovery of a major genetic region, or quantitative trait locus (QTL), associated with salinity tolerance and named Saltol.

Photo: IRRI

Abdelbagi Ismail examines rice plants in the field in Bangladesh.

Its insertion into well-known rice varieties used by farmers in Bangladesh, Indonesia and The Philippines is part of the revolution taking place in rice research.

Abdelbagi says Saltol was mapped and markers were developed for its use in breeding more salt-tolerant rice varieties. Its salt-tolerance code is now being transferred into several varieties evaluated with IRRI partners in South and Southeast Asia.

“These projects also provided opportunities for both degree training and non-degree training to several of our partners in the countries involved,” he adds.

“Partnerships are crucial for us to build the capacity of the researchers in these countries and to ensure our outputs and outcomes reach the farmers that need them.

“All our partners benefitted from salt-tolerant varieties developed conventionally through this project, and they also provided pipelines for uptake and dissemination by farmers.”

Having developed new lines following the discovery of the Saltol QTL, Abdelbagi’s GCP-supported team trained plant breeders in country programmes to successfully breed for salt tolerance and other stresses.

In this way, Abdelbagi says, they are improving the capacity of researchers in developing countries to take up new breeding techniques, such as the use of molecular markers. “This can reduce the time it takes to breed new varieties, from six to ten years at the moment, down to two or three years,” he says.

This means that benefits to smallholder rice farmers struggling with salinity will happen sooner rather than later. And Abdelbagi credits GCP’s partnership approach, working directly with the countries in need, for the success so far.

“The salt-tolerant varieties are now being widely distributed,” he says. “Some of these varieties have doubled farmers’ productivity in affected areas.

“The work developed technologies of value to our needy farmers.

“We do believe this is the start of a second Green Revolution, especially for those who farm in less favourable areas and that missed this opportunity during the first Green Revolution.”

Partnership approach key to new rice gene for uptake of phosphorus

More than 60 percent of rainfed lowland rice is produced on poor and problem soils, including those that are naturally low in phosphorus. This is an essential for nutrient growing crops, but providing phosphorus through fertilisers is costly and unfeasible for many smallholder rice growers.

Photo: IRRI

IRRI’s Sheryl Catausan prepares the roots of a rice plant for scanning as part of the work of the PSTOL1, phosphorus uptake research team at IRRI.

This problem was the focus of GCP’s rice phosphorus-uptake project led by IRRI molecular biologist Sigrid Heuer.

The project was enormously successful, with its discovery of the PSTOL1 (‘phosphorus starvation tolerance 1’) gene within the Pup1 locus, which was published in the prestigious journal Nature.

“We wanted it in Nature for a couple of reasons,” she says. “To raise awareness about phosphorus deficiency and phosphorus being a limited resource, especially in poorer countries; and to draw attention to how we do molecular breeding these days, which is a speedier, easier and more cost-effective approach to developing crops that have the potential to alleviate such problems.”

Following the PSTOL1 discovery, researchers are now working with developing-country researchers and extension agencies to help them understand how to breed local varieties of rice that can be grown in phosphorus-deficient soils. They are also collaborating with other crop breeders looking to breed similar maize, sorghum and wheat varieties.

Tobias Kretzschmar, a molecular biologist with IRRI, says that GCP’s partnership approach was the key to the project having an impact on the rice farmers who needed it most.

“For me, the collaborations that were forged through these inter-institutional projects made the difference,” he says.

Sigrid agrees: “GCP was always there supporting us and giving us confidence, even when we were not sure.”

Solving the insoluble: a gene for drought tolerance

Rice is a crop that not only needs water, but loves water. So developing a drought-tolerant rice variety is a quest to find a seemingly impossible gene.

However, GCP-supported researchers did just that: they solved the insoluble.

“They were very successful in terms of getting drought tolerance,” says Hei Leung of IRRI, who was GCP Subprogramme Leader for the Comparative Genomics Research Initiative between 2004 and 2007, and also a Principal Investigator for the Rice Research Initiative. “They’re now getting a 1.5 tonne rice yield advantage under water stress. I mean, that’s unheard of! This is a crop that needs water.

“This is one of GCP’s big success stories; that you can actually get drought tolerance is a seemingly impossible task for a water-loving rice plant.”

As Subprogramme Leader, Hei played a critical role in the creation, management, delivery and communication of a wide portfolio of research projects. He credits the nature of how GCP was set up for accelerating the breeding programme for drought-tolerant rice.

“The advantage of GCP is that it is run by a small group of people who can make fast decisions,” he says. “This means they can respond to the needs of researchers: ‘Okay, we are going to invest on that. We’re going to have a meeting on this’.

“The real advantage of GCP is its agility. Usually with other organisations you have new ideas and then have to slave away for a year to get the funding to implement them. But GCP was quick.”

Photo: C Quintana/IRRI

Hei Leung (right) explains rice screening processes to a visiting scholar at IRRI.

IRRI and GCP deliver genetic resources to those who need them most

Tobias says one of the main objectives of GCP and IRRI is to make genetic stocks available to breeders, particularly in developing countries.

“Without that, IRRI would fail in its central mission to reduce hunger and poverty,” he says. “In order to achieve this mission, tight collaboration with our agricultural and extension partners in other countries is the key.”

What is a genetic stock? “A genetic stock is a line that has been created by modern breeders and researchers, using conventional technologies, specifically to address some specified scientific purpose, typically for gene discovery,” explains Ruaraidh Sackville Hamilton, an evolutionary biologist and head of the International Rice Genebank maintained by IRRI in The Philippines. This definition includes the notion of perpetuation (a ‘line’), which is central to genetic stocks: either the materials are genetically stabilised through sexual reproduction, or they can be distributed through vegetative propagation.

In fact, this idea of protecting the future through genetic material was influential in the choice of GCP as a CGIAR Challenge Program name. Hei, who was involved from the start with GCP, talks about the meeting in a Rome pizzeria where participants came up with the name: “When we talk about ‘generation’, we are really talking about the work we do with genetic diversity; it is about the future generation,” he says.

Part of that future generation is about sharing genetic resources or stocks, but first the genetic diversity of such stocks needs to be characterised. Hei remembers that one of the first GCP projects in 2004 brought together researchers in various countries to characterise the genetic diversity of various crops, including rice.

“But everyone was using different genotyping platforms and markers, and the technology back then was not what we have now,” he recalls.

“So we spent a lot of resources getting poor quality data. In a sense, it was a failure. On the other hand, it was also a success because we alerted people to the importance of characterising diversity in every single crop. The whole concept of getting all the national partners doing genetic resource characterisation is a good one.

“We have evolved the technology together over the last 10 years of GCP. Now the country partners feel enabled. They are not scared of the technology.”

Abdelbagi agrees that characterising genetic diversity is essential, and adds that making such genetic stocks readily available to breeders is also vital.

“This has not been an issue before,” he explains. “With the new regulations of germplasm control and intellectual property issues, it became extremely difficult to exchange germplasm with some countries. One important lesson we learnt was to engage in direct discussion with our partners in efforts to influence their policies and guidelines to allow essential exchange of genetic stocks and breeding material, at least at the regional level.”

Abdelbagi adds that another big challenge has been to provide country partners with materials and DNA markers for marker-assisted selection programmes and to make sure these were properly used in breeding programmes.

“We solved this by hosting a workshop at IRRI and with continued visits with GCP collaborators,” he says.

Photo: IRRI

Rice terraces in Ifugao Province in The Philippines.

‘Super’ crops: something ‘magic’ happens

Hei says that the GCP project he’s most passionate about, and one that leaves a lasting legacy, is the development of multiparent advanced generation intercross (MAGIC) populations, which will potentially yield lines that are tolerant to environmental stresses, grow well in poor soils and produce better quality grain.

“MAGIC populations will leave behind a very good resource towards improving different crop species,” says Hei. “I’m sure that they will expand on their own.”

Making MAGIC MAGIC – multiparent advanced generation intercross – allows crop breeders to identify the genes controlling quantitative traits, such as salinity tolerance, by crossing different combinations of multiple parents. The results of these crosses are plants whose genome is a mosaic of their multiple parents. MAGIC has multiple advantages compared with existing approaches, as it permits a more precise identification of genes that are responsible for particular rice traits. Even genes with minor effects can be pinpointed. Standard crosses (between two parents) show a poor correlation between the diversity found in the DNA (genetic diversity) and the diversity of the observable characteristics displayed by the plant (phenotypic diversity) when it grows as part of a crop. Because the MAGIC populations are created from multiple parents rather than by simply crossing two lines, making them more genetically diverse, and are the product of numerous generations of intercrossing the original founders or parent plants, creating greater opportunities for recombination and so ‘milling’ the genetic contributions from the different lines ever finer, scientists are able to more accurately identify the genes underlying important traits.  There are three main advantages of the MAGIC approach compared to existing approaches: 1. It enables scientists to more precisely identify the specific regions of the genome controlling key traits. 2. MAGIC populations incorporate a large proportion of the genetic diversity within elite rice varieties from around the world. 3. MAGIC enables the discovery of the best combinations of genes for important traits.

GCP funded the development of four kinds of rice populations, including indica MAGIC, which is the most advanced of the MAGIC populations developed so far. These populations contain multiple desirable traits, including: blast and bacterial blight-resistance, salinity and submergence tolerance and grain quality.

New generation of researchers working on a new rice revolution

Photo: IRRI

Rice farmer in her field in Rwanda.

Robert Zeigler’s dream of a new rice Green Revolution with ‘super crops’ is coming true, thanks in part to GCP’s focus on combining cutting-edge molecular plant-breeding techniques with conventional plant breeding.

“With all this going for us, the second Green Revolution means we can meet the great challenges ahead with unprecedented efforts that will result in unparalleled impacts,” he says. “This will range from mining the rice genomes for needed traits to developing climate change-ready rice.”

IRRI researchers like Abdelbagi agree that new plant-breeding techniques, such as those fostered by GCP, are making ‘super’ crops more likely: “I’m committed to understand how plants can be manipulated to adapt to, and better tolerate, extreme environmental stresses, which seems more feasible today than it has ever been before.

“GCP-supported work has provided mechanisms for developing varieties with multiple stress tolerances, besides the improvements in yield and quality.”

And for Hei, GCP’s 10-year legacy is not just about the technology but also about the people.

“Over ten years you have three generations of PhD students,” he says. “Many people became a ‘new generation’ scientist through this programme. Many people have benefitted. GCP is one of a kind. I’m just in love with it.”

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Jan 302015
 

“Little had been done to advance the genetic diversity of lentils.” This was the picture back in 2005, recalls Aladdin Hamwieh, a scientist at the International Center for Agricultural Research in the Dry Areas (ICARDA) based in Lebanon.

“Lentil has a narrow genetic base, meaning not too many varieties are used in production,” he explains.

Photo: ICARDA

A small sample of the lentil diversity available in the ICARDA gene bank.

It was on this premise that Aladdin joined a three-year global effort to capture and understand the genetic diversity of the world’s lentil varieties – a protein-rich crop that plays an integral part in the lives of many people in Central and West Asia and North Africa (CWANA), South Asia and North America.

He was funded by the CGIAR Generation Challenge Programme (GCP) to develop a refined set of genetic reference materials for lentils so that plant breeders across the globe could access the best gene pool available to be able to improve food security in developing countries.

“Essentially, the genetic make-up of lentil was repeatedly filtered until 15 percent of ICARDA’s gene bank was collected,” says Aladdin.

ICARDA has the largest collection of lentil genes in the world. Some work had been done on improving the genetics of lentils to withstand harsh, dry conditions. But it was not enough to prepare for the challenge the world is now facing – feeding almost 10 billion people by 2050 and climate conditions that mean longer dry periods and more erratic rainfall.

ICARDA has a global mandate for research on lentil improvement. As such, ICARDA houses the world’s collection of lentils, held in trust as a global public good. It includes 8,789 different types of seed of cultivated lentils from 70 countries, 1,146 breeding lines and 574 new seed samples from 4 wild lentil species representing 23 countries. From this, a collection of 1,000 plants was identified for use as GCP reference materials, consisting of traditional farmer varieties, wild relatives and elite varieties and cultivars. Individual plants of each were planted in 2005 so that seed could be collected at the end of the growing season.

The reference set captures the existing genetic diversity of lentils and makes it easier for scientists to search for genes that can help overcome the challenges to lentil production. It consists of about 150 accessions, or 15 per cent of the global collection studied (see box).

Creating the reference set immediately helped researchers to understand more about lentils. “The major outcome was that different gene pools were identified where accessions from Europe and America were clearly separated from Asia and Africa,” Aladdin says. “Accessions from India, Afghanistan and Pakistan were also separated from accessions from the Middle East and North Africa.”

A common resource for lentil breeders

International cooperation and knowledge sharing are hallmarks of GCP, with one of the Programme’s key goals being to facilitate collaboration between scientists from across the globe in breeding new varieties of crops that can not only tolerate drought, but also resist diseases and tolerate poor soils. Ashutosh Sarker, a former lentil breeder and currently Coordinator and Food Legume Breeder for ICARDA’s South Asia and China Regional Program, says production challenges for lentils vary from country to country. While demand is rising globally, he says, some developing countries are having trouble meeting their own need for this staple food.

Photo: P Casier/CGIAR

A woman farmer with lentils in Bihar, India.

This was where the GCP work came in; its purpose, according to Aladdin, was to “develop a diverse reference set that is small and easy to handle. This way, it can be sent around the world for scientists to simultaneously screen for desirable or undesirable traits. This has important implications for developing countries.”

The reference collection serves as a common resource for all lentil breeders interested in the same crop.

“These materials can be accessed to achieve farming goals – to produce tough plants suitable for local environments. In doing this, farmers have a greater likelihood of success, which ultimately improves the wider population’s food security.”

When Aladdin’s team studied the reference collection, they were able to identify favourable genes.

“This enables us to look at the genes of plants and highlight those traits that best suit certain environments,” he says, “and then breed plants to be better adapted.”

Lentils – with a protein content ranging from 22 to 35 percent – are an important source of dietary protein in both human and animal diets, second only to soya beans as a source of usable protein. Lentils are currently grown on 3.8 million hectares worldwide, with a total annual production of over 3.5 million tonnes. The major producers of lentils are countries the South Asia and CWANA regions, and Canada, Australia and the USA. Productivity is low in developing countries, largely because the crop is grown on marginal lands in semiarid environments, without irrigation, weeding or pest control.

Diversity is key to searching for valuable breeding traits

Shiv Kumar Agrawal, who joined ICARDA in 2009, uses the reference set developed for GCP to identify and create markers for drought-tolerant and early-maturing traits for key lentil-producing countries, including Bangladesh, Ethiopia and India.

“Developing more markers will help mitigate lentil’s barriers to production,” says Shiv, pointing to climate change and rising temperatures in production zones as adversely affecting lentil yields.

Markers are like genetic ‘tags’ that indicate which plants or seeds have particular genes, so markers related to relevant genes – for traits such as heat tolerance, for example – can help breeders choose which plant materials to use when developing a new variety.

“Breeding for this should be a priority,” he continues. “Developing heat-tolerant lentil plants would help to expand the area of legume cultivation, stabilise yield in areas prone to heat stress and mitigate impacts of global climate change in the future.”

This is the same for other traits, he says, which would improve food security in developing countries: “Developing extra-early breeds of lentils has great scope in diversifying cropping methods and gives more flexibility for farmers.”

Photo: T Wolday/Bioversity International

Farmers in Ethiopia winnow orange lentils.

Karthika Rajendran, a postdoctoral student working with Shiv at ICARDA, uses both conventional and molecular-breeding approaches to develop heat-tolerant lentil cultivars that mature early. The products of GCP, she says, are “helpful to identify the source of genetic diversity and molecular markers for the traits identified under each research targets.”

Like Shiv, Karthika stresses the value of heat-tolerant varieties for heat-stressed areas and in reducing the impacts of climate change, and adds that improving other traits alongside also has significant impacts: “The development of machine-harvestable lentils reduces the production cost, increases the farm profit, reduces the drudgery of women and improves the nutritional and food security of smallholder farmers in developing countries.”

Photo: E Huttner/ACIAR

Farmer Minto with lentils in his field in Bangladesh.

While achieving such lentil varieties may be some way down the track, Shiv and Karthika offer a small glimpse of what the future holds and the promise of making even more from GCP’s genetic reference set than what has been achieved so far.

Preserving genetic resources

Aladdin Hamwieh is also looking to the future: “We don’t know what tomorrow brings, so people need to understand the value of such genetic reference material.”

He reflects on the reality of how civil unrest in developing countries often means local agriculture is disrupted and crops destroyed, which can mean the loss of traditional varieties.

“We could lose interesting genes from these,” says Aladdin. “We must therefore maintain and protect the ICARDA database, because it stores important information that the next generation won’t be able to study in nature.”

Aladdin is adamant that this is important not only for developing countries but for the whole world. “We can’t make genes in future so this one we cannot lose,” he stresses.

A ‘backup’ duplicate copy of ICARDA’s lentil collection is stored in the Arctic Circle at the Svalbard Global Seed Vault.

Groundwork on lentils ‘gave orientation to future breeding efforts’

Although GCP’s genetic research work on lentils came to an end in 2007, scientists all over the world can still access the materials – and are reaping other benefits from GCP’s work too. For example, ICARDA is using GCP’s Integrated Breeding Platform (IBP) – particularly the Breeding Management System (BMS) – for its lentil-breeding programme.

Reflecting GCP’s collaborative spirit, Shiv explains that his team have not only successfully integrated use of BMS within their own programme, but have also included it in regular training programmes for developing country partners.

Karthika says, “We use the BMS to store historical data of crossing blocks and germplasm collections and to create fieldbooks, field maps and labels of yield trials. We use the crossing manager to build up the list of the crossing blocks, and the breeding manager to maintain the pedigree of the breeding programme.”

She explains that within the BMS, “the breeding view demonstrated a great potential to analyse the phenotypic and genotypic data for single and multienvironmental conditions,” and notes that “the Molecular Breeding Design Tool would be useful in the process of marker-assisted selection.”

ICARDA plans to implement the BMS to develop fieldbooks for Lentil International Elite Nurseries, using the IBFieldbook tool, and to distribute the books to developing country partners for data collection.

“Once the database is centralised, it will facilitate rapid access to breeding material and easy sharing of knowledge and technology to the developing country partners,” says Karthika.

Such ongoing advances in breeding technologies since the outset of GCP mean the refining process can continue.

“We should not stop,” says Aladdin, encouraging other lentil breeders and researchers to continue their work.

Photo: Bill & Melinda Gates Foundation

A female farmer in India helps to harvest lentils by sifting them after fellow workers have beaten the stalks to remove the seeds from their pods.