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Oct 262015
 

 

Photo: HK Tang/Flickr (Creative Commons)

An Indian patchwork of rice and maize fields.

“Once you’ve cloned a major gene in one crop, it is possible to find a counterpart gene that has the same function in another crop, and this is easier than finding useful genes from scratch” explains Leon Kochian, Professor in Plant Biology and Crop and Soil Sciences at Cornell University, USA, and Director of the Robert W Holley Center for Agriculture and Health, United States Department of Agriculture – Agricultural Research Service.

Leon was the Product Delivery Coordinator for the Comparative Genomics Research Initiative of the CGIAR Generation Challenge Programme (GCP). The Programme set out in 2004 to advance plant genetics in a bid to provide sustainable food-security solutions.

Between 2004 and 2014, GCP invested in projects to clone two genes and deploy them in elite local varieties. The first gene, SbMATE, encodes aluminium tolerance traits in sorghum; the work was a collaborative effort led by the Brazilian Corporation of Agricultural Research (EMBRAPA) and Cornell University, and gave rise to locally-adapted sorghum varieties released in South America and Africa. The second gene, PSTOL1, produces traits that improve phosphorus uptake in rice. This research was a collaboration between the Japan International Research Center for Agricultural Sciences (JIRCAS) and the International Rice Research Institute (IRRI). PSTOL1 has now been extensively deployed in Asian rice varieties.

Aluminium toxicity and low phosphorus levels in acid soils are major factors that hinder cereal productivity worldwide, particularly in sub-Saharan Africa, South America and Southeast Asia. Globally, acid soils are outranked only by drought when it comes to stresses that threaten food security.

Tolerance to high levels of aluminium and low phosphorus is conferred by major genes, which lend themselves to cloning. Major genes are genes that by themselves have a significant and evident effect in producing a particular trait; it’s therefore easier to find and deploy a major gene associated with a desired trait than having to find and clone several minor genes.

Photo: S Kilungu/CCAFS

Harvesting sorghum in Kenya.

Cloning major genes instrumental in hunt for resilient varieties

Locating a single gene within a plant’s DNA is like looking for a needle in a haystack. Instead of searching for a gene at random, geneticists need a plan for finding it.

The first step is to conduct prolonged phenotyping – that is, measuring and recording of plants’ observable characteristics in the field. By coupling and comparing this knowledge with genetic sequencing data, scientists can identify and locate quantitative trait loci (QTLs) – discrete genetic regions that contain genes associated with a desired trait, in this instance tolerance to aluminium or improved phosphorus uptake. They then dissect the QTL to single out the gene responsible for the desired trait. In the case of sorghum, researchers had identified the aluminium tolerance locus AltSB, and were looking for the gene responsible.

Once the gene has been identified, the next step is to clone it – that is, make copies of the stretch of DNA that makes up the gene. Geneticists need millions of copies of the same gene for their research: to gain information about the nucleotide sequence of the gene, create molecular markers to help identify the presence of the gene in plants and help compare versions of the gene from different species, and understand the mechanisms it controls and ways it interacts with other genes.

Photo: ICRISAT

Drying the sorghum harvest in India.

Sorghum was one of the simpler crops to work with, according to Claudia Guimarães.

“Sorghum has a smaller genome… with clear observable traits, which are often controlled by one major gene,” she says.

The first breakthrough was the identification and cloning of SbMATE, the aluminium tolerance gene in sorghum behind the AltSB locus. The next was finding a diagnostic marker for the gene so that it could be used in breeding.

Marking genes to quickly scan plants for desired traits

Photo: IRRI

Harvesting rice in The Philippines.

Once a desired gene is identified, a specific molecular marker must be found for it. This is a variation in the plant’s DNA, associated with a gene of interest, that scientists can use to flag up the gene’s presence. We can compare this process to using a text highlighter in a book, where the words represent the genes making up a genome. Each marker is like a coloured highlighter, marking sentences (genomic regions) containing particular keywords (genes) and making them easier to find.

In molecular breeding, scientists can use markers to quickly scan hundreds or thousands of DNA samples of breeding materials for a gene, or genes, that they want to incorporate into new plant varieties. This enables them to select parents for crosses more efficiently, and easily see which of the next generation have inherited the gene. This marker-assisted breeding method can save significant time and money in getting new varieties out into farmers’ fields.

Leon, who was also the Principal Investigator for various GCP-funded research projects, says that the cloning of SbMATE helped advance sorghum as a model for the further exploration of aluminium tolerance and the discovery of new molecular solutions for improving crop yields.

“This research also has environmental implications for badly needed increases in food production on marginal soils in developing countries,” says Leon. “For example, if we can increase food production on existing lands, it could limit agriculture’s encroachment into other areas.”

Photo: IRRI

Rice field trials in Tanzania.

Aluminium toxicity is the result of aluminum becoming more available to plants when the soil pH is lower, and affects 38 percent of farmland in Southeast Asia, 31 percent in South America and 20 percent in East Asia, sub-Saharan Africa and North America. Meanwhile phosphorus, the second most important inorganic plant nutrient after nitrogen, becomes less available to plants in acid soils because it binds with aluminium and iron oxides. Almost half of the ricelands across the globe are currently phosphorus deficient. The research therefore has the potential for significant impact across the world.

The GCP-funded scientists used markers to search rice and maize for genes equivalent to sorghum’s SbMATE. In maize they successfully identified a similar gene, ZmMATE1, which is now being validated in Brazil, Kenya and Mali. In rice the search continues, but will become easier now that markers for ZmMATE1 have been developed.

Similarly, having validated, cloned and developed markers for PSTOL1 gene in rice, researchers at IRRI and JIRCAS then worked with researchers at EMBRAPA and Cornell University to use PSTOL1 markers to search for comparable genes in sorghum and maize. In both crops, genes similar to PSTOL1 have been identified and shown to improve grain yields under low-phosphorus soil conditions, albeit through different mechanisms.

The GCP-funded discoveries are already being used in marker-assisted selection in national breeding programmes in Brazil, Kenya, Niger, Indonesia, Japan, The Philippines and USA in sorghum, maize and rice. They have led to the release of new, aluminium-tolerant sorghum varieties in Brazil, with more currently being developed, along with phosphorus-efficient rice varieties.

Photo: S Kilungu/CCAFS

Showing off freshly harvested sorghum in Kenya.

Cloning a worthwhile investment

Gene cloning was a relatively small cost in GCP’s research budget – about five percent (approximately USD 7 million) of a total research budget of USD 150 million spread over 10 years.

The gene-cloning component nonetheless yielded important genes for aluminium tolerance and phosphorus-uptake efficiency, within and across genomes. The molecular markers that have been developed are helping plant breeders across the world produce improved crop varieties.

Jean-Marcel Ribaut, Director of GCP, concludes: “The new markers developed for major genes in rice, sorghum and maize will have a significant impact on plant-breeding efficiency in developing countries.

“Breeders will be able to identify aluminium-tolerance and phosphorus-efficiency traits quicker, which, in time, will enable them to develop new varieties that will survive and thrive in the acid soils that make up more than half of the world’s arable soils.”

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Photo: CSISA

A rice farmer in Bihar, India.

Sep 242015
 

Hei Leung has always been passionate about diversity, especially genetic diversity, and that’s one reason why he leapt at the chance to get involved with the CGIAR Generation Challenge Programme (GCP) right from its inception more than a decade ago.

Photo: IRRIBut GCP’s attraction for Hei wasn’t just about genetic diversity; it was also about working with diverse institutes and researchers. At the time, Hei had been working for the International Rice Research Institute (IRRI) for some 10 years, on and off, including a stint at Washington State University in the USA.

“The whole idea of the Challenge Programme was to bring people together from different places instead of an individual CGIAR Centre doing things,” he says.

Hei also saw the likely spin-offs from rice research to other crops such as wheat, maize and sorghum, which are also crucial to food security.

Rice is a ‘model crop’ because of its small genome. This means researchers in major cereals like wheat and maize, which have much bigger genomes but share genes of similar functions, can benefit from our work with rice.”

Photo: Jeffreyw/Flickr (Creative Commons)

From little pizzas great programmes grow!

It all began in 2003, over pizza, in Rome. Hei remembers that his commitment to GCP started when he met with a small group of people including Robert Zeigler, who was to become the first Director of GCP, and who is currently Director General of IRRI.

“Little did we know that pizza was so inspiring,” Hei says, recalling that it was during that meeting that they agreed on the name: the Generation Challenge Programme.

GCP was formally launched in 2004 in Brisbane, Australia, at the 4th International Crop Science Congress.

Making the Programme ‘pro-poor’

Hei was initially involved with GCP as Subprogramme Leader for Comparative Genomics for Gene Discovery between 2004 and 2007, and later as a Principal Investigator for the Rice Research Initiative. Taking on his leadership role, Hei recognised from the start that many crops important to developing communities in Asia and Africa needed to become more drought-tolerant because of the increasing effects of climate change.

“We wanted to have a programme that is what we call ‘pro-poor’,” he says. “The majority of the world’s people depend on crops such as rice, wheat and maize for food.”

“I always feel that if you can solve eastern India’s problems, you can solve most of the problems in the world,” Hei adds. “If you travel in eastern India, you can see climate change happening day in, day out. You don’t have to wait 10 years or 50 years; it’s happening already. They either have too much or too little water. It’s a high-stress environment.”

Photo: N Palmer/CIAT


Women at work threshing rice near Sangrur, Punjab, India.

Rice is the world’s most widely consumed cereal crop, and is particularly important as the staple food of 2.4 billion people in Asia. GCP recognised rice’s importance and invested almost USD 29.5 million in rice research and development.

Furthermore, the genetic breeding lessons learnt from rice can also be applied to other staple crops such as wheat, maize and sorghum.

Other GCP-supported researchers used comparative genetics to determine if the same or similar genes – for example, the phosphorus starvation tolerance (PSTOL1) protein kinase gene found in rice – was also present and operating in the same manner in sorghum and maize.

They found sorghum and maize varieties that contained genes, similar to rice’s PSTOL1, that also conferred tolerance to phosphorus-deficient soils by enhancing the plant’s root system. They were then able to develop molecular markers to help breeders in Brazil and Africa to identify lines with these genes, which can now be used in breeding and developed as varieties for farmers growing crops, particularly in acidic soils.

Seeing the potential for novel researcher interactions

Hei also recognised that crops that received less scientific attention but remained important as regional staple foods, such as bananas and plantains (of the genus Musa), could benefit from comparative genomics research.

“We had a highly motivated group of researchers willing to devote their efforts to Musa,” remembers Hei, who is currently IRRI Program Leader of Genetic Diversity and Gene Discovery.

“GCP’s community could offer a framework for novel interactions among banana-related actors and players working on other crops, such as rice. So, living up to its name as a Challenge Programme, GCP decided to take the gamble on banana genomics and help it fly.”

Photo:  Asian Development Bank

A banana farmer at work in the Philippines.

However, after four years, Hei found it difficult to maintain his GCP leadership role as well as keep on top of his IRRI work: “They said I was 50 percent with IRRI and 50 percent with GCP, but it is never like that in reality. I was always doing two jobs, or at least one-and-a-half jobs, and I didn’t think I was doing a good enough job for either. I thought it was time for other people to come into GCP.”

While Hei stepped down from a leadership role, he remained active working on GCP projects throughout the life of the Programme.

Hei says that during the last five years of GCP, a lot of technology to characterise genetic diversity evolved “to bring high-quality science to accelerate our mission to help the poor areas of Asia and Africa.”

Streamlining GCP reporting: from three reports a year down to just one One of the things that initially bothered Hei during his GCP time was the reporting requirements: “I remember we used to ask people to submit a mid-year report, end-of-year report and an update. “So I stuck my neck out during the last couple of years, and I said: ‘Guys, stop it. Don’t ask for these reports. They become mechanical. People just fill in the blanks. Ask for just one report before or after our annual meeting: just one report that people are excited to write about. And that was adopted.”

A MAGIC affair

The development of MAGIC (multi-parent advanced generation intercross) populations is the project that Hei gets most excited about. From these populations, created by crossing different combinations of multiple parents, plant lines can be selected that have useful characteristics such as drought tolerance, salinity tolerance and the ability to produce better quality grain.

“Now many crop breeders are calling for MAGIC populations,” says Hei. “I feel proud that at GCP we decided to support this concept and activity. This is one of GCP’s most important legacies and it’s one of my most favourite things.”

Photo: IRRI

Hei Leung looking relaxed in the lab at IRRI.

Honoured as a Fellow of the American Phytopathological Society (APS), Hei is recognised “for his leadership in the international community toward building and distributing rice genetic and genomic resources and creating capacity in plant pathology in the developing countries of Asia.”

Hei’s GCP leadership and research have clearly provided him with an important platform for taking on leadership and champion roles linking many individuals and organisations across Asia and Africa. His ASP profile concludes: “His promotion of collaborative research and his leadership in such programmes in the developing world have contributed to the building of a dynamic research community that promotes both basic knowledge and food security for Asia and the world.”

Making a difference to food security and farmer’s lives in developing countries is what GCP is all about. Such differences have been made possible through collaborative links that connect a diversity of organisations and people with the latest research in genetic diversity and breeding techniques.

Photo: IRRI

A farmer transplants rice in the Philippines.

It’s amore!

hei quoteHei recalls his personal and professional journey with GCP with much affection: “I think that it has been a wonderful scientific journey in terms of knowing the science and opening up my mind to being more receptive to alternative ways of doing things.

“There have been so many friends I have met through networking with GCP. Sometimes you go through bumpy roads, but anything you do will have bumpy times. And it’s very unusual to have a programme so illuminating. We honoured our commitment to finish in 10 years. It is a programme that had a fresh start and a clean ending.

“Most importantly, GCP has enabled plant breeders to embrace cutting-edge science through partnerships that focused on improving crop yields in areas previously deemed unproductive,” he says. “GCP is unique, one-of-a-kind, and I love it!”

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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.

May 292015
 

A little over a decade ago, a PhD student in Brazil was poring over sorghum genes, trying to isolate one that helps plants withstand acidic soils.

Photo: B Nichols/USDA

Sorghum

Scientists at the Brazilian Corporation of Agricultural Research (EMBRAPA) had been researching plants that can grow well in acidic soils since the mid-1970s.

“What we have done within the Generation Challenge Programme,” explains Jurandir Magalhães, now a senior scientist for EMBRAPA, as he reflects back on the past decade, “is speed up maize and sorghum breeding for acidic soil adaptation”.

EMBRAPA partnered with the CGIAR Generation Challenge Programme (GCP) to advance plant genetics so as to breed aluminium-tolerant crops that will improve yields in harsh environments, in turn improving the quality of life for farmers.

Almost 70 percent of Brazil’s arable land is made up of acidic soils. That means the soil has toxic levels of aluminium and low levels of phosphorous – a lethal combination that makes crop production unsustainable. Aluminium toxicity in soil comes close to rivalling drought as a food-security threat in critical tropical food-producing regions. This is because acidic soils reduce root growth and deprive plants of the nutrients and water they need to grow.

Robert Schaffert – EMBRAPA’s longest-serving sorghum breeder – had developed mapping populations for aluminium tolerance in sorghum; these populations were the basis for the work supported by GCP.

During the first four years of the 10-year Programme, Jurandir was able to identify and clone the major aluminium-tolerance gene in sorghum – AltSB – using these mapping populations. The cloned gene has since enabled researchers across Africa and Asia to quickly and efficiently breed improved sorghum and maize plants that can withstand acidic soils.

Jurandir, speaking today about the work to advance sorghum genetic resources, says: “Wherever there are acidic soils with aluminium toxicity and low phosphorous availability, our results should be applicable.”

His story with EMBRAPA is one of many where GCP-supported projects have been instrumental in helping global research centres achieve their goals, which ultimately will help farmers worldwide.

Common objectives

Jurandir is now a research scientist in molecular genetics and genomics at the EMBRAPA Maize & Sorghum research centre. He and colleagues at the centre partnered with scientists in Africa, Asia and the US to identify and clone genes in sorghum, maize and rice that confer resistance or tolerance to stresses such as soil acidity, phosphorus efficiency, drought, pests and diseases.

Photo: R Silva/EMBRAPA

Maize growing in Brazil.

“One important focus of GCP was linking basic research to applied crop breeding,” Jurandir says. “This is also the general orientation of our programme at EMBRAPA. We develop projects and research to produce, adapt and diffuse knowledge and technologies in maize and sorghum production by the efficient and rational use of natural resources.

“GCP provided both financial support and a rich scientific community that were useful to help us attain our common objectives.”

EMBRAPA’s work on cloning the AltSB gene would prove to be one of the first steps in GCP’s foundation sorghum and maize projects, both of which sought to provide farmers in the developing world with crops that will not only survive but thrive in the acidic soils where aluminium toxicity reduces crop production.

Leon Kochian of Cornell University in the US was Jurandir’s supervisor at the time when they applied for GCP funding. Leon was a Principal Investigator for various GCP research projects, researching how to improve grain yields of crops grown in acidic soils.

“The breeders are so important,” says Leon about the importance of supporting institutes such as EMBRAPA to advance plant genetics. “Ultimately, they are the cliché of ‘the rubber hits the road’. They’re the ones who translate what we’re trying to figure out into the actual crop improvements. That’s really what it’s all about.”

“That’s why EMBRAPA is a unique institution. Their mission is to get improved seed out, new germplasm out, for the farmers. They have the researchers in sorghum and maize breeding [Robert Schaffert and Sidney Parentoni] and molecular biology [Jurandir Magalhães and Claudia Guimarães].”

Photo: CIFOR

Maize farmers in Brazil.

Great minds think alike

Jurandir’s EMBRAPA colleague Claudia Guimarães, a plant molecular geneticist focusing on maize, says GCP promoted ‘products’, which also echoed the mission statement of EMBRAPA’s Maize & Sorghum research centre.

The centre’s mission is to: ‘Generate, adapt and transfer knowledge and technology that allows for the efficient production and use of maize, sorghum, and natural resources as well as promotes competitiveness in the agriculture sector, sustainable development, and the well-being of society.’

GCP, says Claudia, “wanted to extract something else from the science – products – the idea of a real, touchable product. You have to have progress: germplasm, lines, markers; they are quite practical things.

“The major goal of GCP is to deliver products that can improve people’s lives worldwide. So it needs to be readily available and useful for other scientists and for the whole community.”

GCP wanted to ensure that research products could and would be adopted, adapted and applied for the ultimate benefit of resource-poor farmers. The Programme therefore set out to catalyse interactions between the various players who are needed to bridge the gap between strategic research in advanced labs and resource-poor farmers.

GCP and EMBRAPA were both working towards tangible applied outcomes, says Claudia: “GCP was not only giving you money, they are really serious about what are you doing: ‘Did you deliver everything you promised?’”

Claudia delivered. She and her team at EMBRAPA were able to find an important aluminium-tolerance gene in maize similar to the sorghum gene. This outcome provided the basic materials for molecular-breeding programmes focusing on improving maize production and stability on acidic soils in Africa and other developing regions.

Photo: L Kochian

Maize trials in the field at EMBRAPA. The maize plants on the left are aluminium-tolerant while those on the right are not.

Multifaceted and tangible results

Through further GCP funding, EMBRAPA researchers Robert Schaffert and Sidney Parentoni were able to work together with two researchers from Kenya, Dickson Ligeyo and Samuel Gudu, to develop a breeding programme to combine the improved Brazilian germplasm with locally adapted Kenyan materials. A new base of improved germplasm was established for Kenyan breeders, which allowed the development of varieties adapted to acidic soils in Kenya.

Sidney, a maize breeder for GCP projects and now the deputy head of research and development for EMBRAPA Maize & Sorghum, says that the benefits of being part of GCP are multifaceted: “It was very important, not only for EMBRAPA as an institute, but also individually for each of the participants that had the opportunity to interact with partners in different parts of the word,” says Sidney.

Photo: Bioversity International

A Kenyan farmer with her sorghum crop.

“Each of them adds a piece to build the results achieved by GCP, which from my perspective promoted a number of advances in the areas of genetics and breeding.

“Technologies such as root image scanning developed at Cornell [University] were transferred to EMBRAPA and allowed us to do large-scale screening in a number of maize and sorghum genotypes with large impacts in phosphorous-efficiency studies.

“Scientists from Africa were trained in breeding and screening techniques at EMBRAPA, and Brazilian scientists had the opportunity to go to Africa and interact with African researchers to jointly develop strategies for breeding maize and sorghum for low-phosphorous and acidic soils.

“These trainings and exchanges of experiences were very important for the people and for the institutions involved,” says Sidney.

Sustainable partnerships to break ground for groundnut

Photo: N Palmer/CIAT

Groundnut

Soraya Leal-Bertioli is a researcher in the EMBRAPA Genetic Resources & Biotechnology centre. She works on groundnut (also known as peanut), and formed part of the GCP team working on groundnut with tolerance to drought and resistance to diseases and fungal contamination. She concurs that GCP united researchers from all over the globe in a common goal.

“GCP not only identified groups, but it went out, searched for people and invited contributions, offered resources to get them together. GCP brought partnerships to a whole new level,” Soraya says.

“Last time I checked there were 200 partners in 50 countries. No one is able to do that. It required a lot of money, a lot of resources, but the way it was dealt with in GCP was: ‘Let’s reach out for the main players, the ones who have the technology, and also the ones who can use the technology’.

“GCP used the resources for the benefit of the community and brought everybody together.”

Soraya says the traditional way of funding research often had ‘no structure’.

“Sometimes a university or funding body receives a large amount of money and decides to build something, a new institute in the middle of the jungle somewhere, but they don’t have anybody to run it; it is not sustainable.

“What GCP did was help to provide the structure and the agents for the whole system. They helped train the people to run the whole system. This is a very sustainable model, which is very likely to give good results in a much shorter time frame than other programmes.”

Watch Soraya – and other members of the team – discuss the complex personality of groundnut and groundnut research in our video series:

Genetic stocks AND people are products

The products and outcomes of the collaboration with GCP have included both the tangible and the not-so-tangible. Sidney says that a large quantity of Brazilian improved maize and sorghum lines tolerant to acidic soils has been developed over the years at EMBRAPA.

“These materials were shared with partners in Africa, and this was a major contribution to Kenyan farmers, as part of this collaborative work done in the scope of GCP.

“To be part of the programme has been very important for EMBRAPA’s research team. It has given us the opportunity to interact with a diversity of institutes.”

Sidney mentions institutes they gave worked with through GCP, including Cornell University and Texas A&M University in the US, the Japan International Research Center for Agricultural Sciences (JIRCAS), the International Rice Research Institute (IRRI), the International Maize and Wheat Improvement Center (CIMMYT), and various institutes in Africa, such as Moi University, Kenya, and the Kenya Agricultural and Livestock Research Organisation (KALRO).

Sidney concludes: “In this large network of partnerships, EMBRAPA was able to learn and to share information in a highly productive way.

“From my perspective, the involvement with GCP projects allowed me to grow as a researcher and as a person, and also at the same time to share and to acquire new knowledge in a number of areas. I think it was a ‘win-win’ interaction for all the participants.”

Many of the products generated within the scope of GCP, such as markers and germplasm, are already available within EMBRAPA’s breeding programmes. Avenues for further research have been paved based on the GCP achievements, and these new research lines will be continued within new projects.

As Claudia says: “The strong partnerships built along the way with GCP will be maintained by us joining with new research teams from other institutes and countries to work on new projects.”

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Dec 052014
 

It’s a cruel feature of some of the most populous areas of the world, particularly in the tropics and subtropics: acid soils. They cover a third of the world’s total land area – including significant swathes of Africa, Asia and Latin America – and 60 percent of land we could use for growing food. Today around 30 percent of all arable land reaches levels of acidity that are toxic to crops.

Soil acidity occurs naturally in higher rainfall areas and varies according to the landscape and soil. But we also make the problem worse through intensive agricultural practices. The main cause of soil acidification is the overuse of nitrogen fertilisers, which farmers apply to crops to increase production. Ironically, the inefficient use of nitrogen fertiliser can instead make matters worse by decreasing the soil pH.

60 percent of the world’s potential crop-growing land is highly acidic. Map courtesy of Leon Kochian.

60 percent of the world’s potential crop-growing land is highly acidic. Map courtesy of Leon Kochian.

Acidity prevents crops from accessing the right balance of nutrients in the soil, limiting farmers’ yields. Its negative effect on world yield is second only to drought and is particularly hard felt by subsistent and smallholder farmers who cannot afford to correct soil pH using calcium-rich lime. As a result, these farmers are forced to grow less profitable, acid-tolerant crops like millet, or suffer huge yield losses when growing more popular cereal crops like wheat, rice or maize.

“In Kenya, acidic soils cover almost 90 percent of the maize-growing areas and can reduce yields by almost 60 percent,” says Samuel Gudu, Professor and Deputy Vice-Chancellor (Planning & Development) at Moi University in Kenya. “Farmers know that the soil affects their yields, but they still grow maize because it is so popular.”

As is true in many other sub-Saharan countries, maize is a staple of the Kenyan diet: the average Kenyan consumes 98 kilograms of it each year. But maize prices in Kenya are among the highest in Africa, which directly affects the poorest quarter of the population, who spend 28 percent of their income on the crop.

“Yield losses play a big part in this economic imbalance and are why we need affordable agronomic options to help our farmers improve yields,” says Samuel, who was a Principal Investigator of a GCP comparative genomics project which sought to provide some of these options.

A Kenyan farmer prepares her maize plot for planting. Acid soils cover almost 90 percent of Kenya’s maize-growing area, and can more than halve yields.

A Kenyan farmer prepares her maize plot for planting. Acid soils cover almost 90 percent of Kenya’s maize-growing area, and can more than halve yields.

Aluminium toxicity and phosphorus deficiency: Public enemies number one and two in the fight against acidic soils

Between 2004 and 2014, crop researchers and plant breeders across five continents collaborated on several GCP projects to develop local varieties of maize, rice and sorghum that can withstand phosphorus deficiency and aluminium toxicity – two of the most widespread constraints leading to poor crop productivity in acidic soils.

Aluminium toxicity is the primary limitation on crop production for more than 30 percent of farmland in Southeast Asia and Latin America and approximately 20 percent in East Asia, sub-Saharan Africa and North America. Aluminium becomes more soluble in acid souls, creating a toxic glut of aluminium ions that damage roots and impair their growth and function. This results in reduced nutrient and water uptake, which in turn depresses yield.

Phosphorus deficiency is the next biggest soil deficiency after nitrogen to limit plant production. In acid soils, phosphorus is stuck (fixed) in forms that plants cannot take up. All plants need phosphorus to survive and thrive; it is a key element in plant metabolism, root growth, maturity and yield. Plants deficient in phosphorus are often stunted.

In a double whammy, the damage that aluminium toxicity causes to roots means that plants cannot efficiently access native soil phosphorus or even added phosphorus fertiliser – and adding phosphorus is an option that is rapidly becoming less viable.

“The world is running out of phosphorus as quickly as it is running out of oil,” says Leon Kochian, a Professor in the Departments of Plant Biology and Crop and Soil Science at Cornell University in the USA. “This is making its application a more expensive and less sustainable option for all farmers wanting to improve yields on acidic soils.” Indeed, the price of rock phosphate has more than doubled since 2007.

For 30 years, Leon has combined lecturing and supervising duties at Cornell University and the United States Department of Agriculture with his scientific quest to understand the genetic and physiological mechanisms that allow some cereals to tolerate acidic soils while others wither. And for the last 10 years, he has played an important leading role in GCP’s effort to develop new, higher yielding varieties of maize, rice and sorghum that tolerate acidic soils.

GCP builds on past crop breeding successes

The rationale behind GCP’s efforts stems from two independent and concurrent projects, which had been flourishing on different sides of the Pacific well before GCP was created.

One of those projects was co-led by Leon at Cornell University in collaboration with a previous PhD student of his, Jurandir Magalhães, at the Brazilian Corporation of Agricultural Research (EMBRAPA) Maize & Sorghum research centre.

Working on the understanding that the cells in grasses like barley and wheat use ‘membrane transporters’ to insulate themselves against excessive subsoil aluminium, Leon and Jurandir searched for a similar transporter in the cells of sorghum varieties that were known to tolerate aluminium.

“In wheat, when aluminium levels are high, these membrane transporters prompt organic acid release from the tip of the root,” explains Jurandir. “The organic acid binds with the aluminium ion, preventing it from entering the root.” Jurandir’s team found that in certain sorghum varieties, the gene SbMATE encodes a specialised organic acid transport protein, which stimulates the release of citric acid. They cloned the gene and found it was very active in aluminium-tolerant sorghum varieties. They also discovered that the activity of SbMATE increases the longer the plant is exposed to high levels of aluminium.

The rice variety on the left (IR-74) has the the gene locus Pup1, conferring phosphorus-efficient longer roots, while the rice on the right does not.

The rice variety on the left (IR-74) has the the gene locus Pup1, conferring phosphorus-efficient longer roots, while that on the right does not.

The other project, co-led by Matthias Wissuwa at Japan International Research Centre for Agricultural Sciences (JIRCAS) and Sigrid Heur at the International Rice Research Institute (IRRI) in The Philippines, was looking for genes that could improve rice yields in phosphorus-deficient soils. They had already identified a gene locus (a section of the genome containing a collection of genes) that produced a protein which allowed rice varieties with to grow successfully in low-phosphorous conditions. The locus was termed ‘phosphorus uptake 1’ or Pup1 for short. With GCP support, the team were able to make the breakthrough of discovering the protein kinase gene responsible, PSTOL1 (‘phosphorus starvation tolerance 1’), and understanding its mechanism.

“In phosphorus-poor soils, this protein instructs the plant to grow larger, longer roots, which are able to forage through more soil to absorb and store more nutrients,” explains Sigrid, a plant geneticist at IRRI and a GCP Principal Investigator. “By having a larger root surface area, plants can explore a greater area in the soil and find more phosphorus than usual. It’s like having a larger sponge to absorb more water.”

Screening for phosphorus-efficient rice, able to make the best of low levels of available phosphorus, on an International Rice Research Institute (IRRI) experimental plot in the Philippines. Some types of rice have visibly done much better than others.

Screening for phosphorus-efficient rice, able to make the best of low levels of available phosphorus, on an International Rice Research Institute (IRRI) experimental plot in the Philippines. Some types of rice have visibly done much better than others.

Leon clarifies that both projects were fairly advanced before they became part of the GCP fold. “Our team had already identified the gene SbMATE and were in the process of cloning it for breeding purposes. The IRRI and JIRCAS team had also identified Pup1 and were in the process of identifying and cloning the gene.”

The purpose of cloning these genes was to create molecular markers to help breeders identify whether the genes were present in the varieties they were working with. As an analogy, think of ‘reading’ a plant’s genome as you would read a story: the story’s words are the plant’s genes, and a molecular marker works as a text highlighter. Different markers can highlight or tag different keywords in the story. Tagging the location of beneficial genes in the DNA of plant genomes allows scientists to see which of the plants or seeds they are interested in – perhaps only a few out of hundreds or thousands – contain these genes. This forms the basis of marker-assisted breeding, which can help plant breeders halve the time it takes them to breed new high-yielding varieties for acidic soil conditions.

Leon says that GCP provided both projects with the opportunity to validate their discoveries and to use what they had found to develop new aluminium-tolerant sorghum varieties and phosphorus-efficient rice varieties for farmers. But it’s what happened next that made this GCP initiative unique.

Finding the best genes within the crop family

Sorghum, rice, maize and wheat are all part of the Poaceae (true grasses) family, evolving from a common grass ancestor 65 million years ago. Over this time, they have become very different from each other. However, at the genetic level they still have a lot in common.

Over the last 20 years, genetic researchers all over the world have been mapping these cereals’ genomes. These maps are now being used by geneticists and plant breeders to identify similarities and differences between the genes of different cereal species. This process is termed ‘comparative genomics’ and was a fundamental research theme for GCP during its second phase (2008–2014).

“The objective during GCP Phase I (2004-2007) was to study the genomes of important crops and identify genes conferring resistance or tolerance to various stresses, such as drought,” says Rajeev Varshney, Director of the Center of Excellence in Genomics at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). “This research was long and intensive, but it set a firm foundation for the work in GCP’s second phase, which sought to use what we have learnt in the laboratory and apply it to breed better varieties of crops.”

Rajeev oversaw GCP’s comparative genomics research projects on aluminium tolerance and phosphorus deficiency in sorghum, maize and rice, as part of his GCP role as Leader of the Comparative and Applied Genomics Research Theme.

“The idea behind the sorghum, maize and rice initiative was to use the discoveries we had independently made in sorghum and rice to see if we could find the same genes in the other crop,” explains Rajeev. “In other words, we wanted to see if we could find PSTOL1 in sorghum and SbMATE in rice.”

Working together through a number of comparative genomics projects, the researchers were highly successful in reaching this goal, discovering valuable sister genes and beginning to introduce them into new improved crop varieties for farmers.

Extending research in sorghum and rice to maize

Researchers at Cornell and EMBRAPA had already been using similar comparative techniques to look for SbMATE in maize because of its close familial connection to sorghum. This research was overseen by Leon and another EMBRAPA researcher, Claudia Guimarães.

“We used the knowledge that Jurandir and Leon’s SbMATE project produced to prove that we had a major aluminium-tolerance gene,” reflects Claudia.

The SbMATE gene in sorghum explains about 80 percent of its aluminium tolerance, but Claudia says that in maize it explains only about 20 per cent, making it harder for researchers to find without a little help knowing what to look for. “So we had to dig a little deeper for other similar genes that confer aluminium tolerance, and we found ZmMATE.”

Maize trials in the field at EMBRAPA. The maize plants on the left are aluminium-tolerant while those on the right are not.

Maize trials in the field at EMBRAPA. The maize plants on the left are aluminium-tolerant while those on the right are not.

ZmMATE1 has a similar genetic sequence to SbMATE and encodes a similar protein membrane transporter that releases citric acid from the roots. Just as in sorghum, citric acid binds to aluminium in the soil, making it difficult for it to enter plant roots. The team have also discovered related gene ZmMATE2, which also encodes a transporter protein, but appears to confer aluminium tolerance via a different mechanism, as yet unclear.

Claudia has developed a number of molecular markers for ZmMATE, which have been successfully used by breeders at EMBRAPA as well as by African partners in Niger and Kenya, such as Samuel Gudu, to identify maize breeding lines that have the gene.

“We used aluminium-tolerant maize varieties sourced locally and from Brazil to develop a range of potential new varieties,” says Samuel. “The goal is to develop varieties that are suited to our environment and not too dissimilar to varieties that Kenyan farmers like to grow, except they have a higher tolerance to aluminium toxicity.”

Left to right (foreground): Leon Kochian, Jurandir Magalhães and Samuel Gudu examine crosses between Kenyan and Brazilian maize, at the Kenya Agricultural Research Institute (KARI), Kitale, in May 2010.

Left to right (foreground): Leon Kochian, Jurandir Magalhães and Samuel Gudu examine crosses between Kenyan and Brazilian maize, at the Kenya Agricultural Research Institute (KARI), Kitale, in May 2010.

Involving farmers in the crop breeding process is an important part of such programs being successful, explains Samuel. “They help us identify maize varieties that they have observed have higher tolerance to acidic soils. We also try to incorporate other features that they want, such as disease resistance and higher yield. By incorporating their feedback into the breeding process they are more likely to grow any new varieties, as they have played a part in their development.”

Samuel says they have developed some local aluminium-tolerant varieties, which rank among the best for aluminium tolerance. Interestingly, these varieties seem to have a different aluminium-tolerance mechanism to the Brazilian varieties.

“From the work Samuel has done, we’ve possibly identified a novel source of aluminium tolerance in Kenyan maize varieties,” says Claudia. “We are now working together with Leon to identify the genes that are conferring this tolerance so we can develop markers to help Kenyan maize breeders also identify these varieties more efficiently.”

To help in the process, Samuel and his team are developing single-cross hybrids with a combination of both the novel Kenyan sources of aluminium tolerance and ZmMATE from Brazil, which will be even more tolerant to acidic soils.

Breeding for multiple stresses is a step-by-step process

Suradiyo, a farmer from Bojong Village near Yogyakarta, Indonesia, harvests rice.

Suradiyo, a farmer from Bojong Village near Yogyakarta, Indonesia, harvests rice.

In Asia, about 60 percent of rainfed rice is grown on soils that are affected by multiple stresses. These typically include phosphorus deficiency as well as aluminium toxicity, salinity and drought.

These stresses are particularly hard felt in Indonesia, which is the world’s third-largest rice producer. Joko Prasetiyono is a molecular rice breeder at the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development (ICABIOGRAD). His team have been collaborating with IRRI and JIRCAS for many years and contributed to validating the effect of Pup1 by embedding it into three popular local rice varieties – Dodokan, Situ Bagendit and Batur – which were then able to tolerate phosphorus-deficient conditions.

“The aim [with GCP research] was to breed varieties identical to those that farmers already know and trust, except that they have PSTOL1 and an improved ability to take up soil phosphorus,” says Joko.

Joko says that these varieties – which will be available in one to two years – will yield as well as, if not better than, traditional varieties, and will need 30–50 percent less fertiliser.

But the work is only partly finished for Joko and his Asian partners. They are now building on previous work done at Cornell and EMBRAPA to include the SbMATE gene in their varieties. “Higher yields will only be possible if the plant can also tolerate excess aluminium, which severely inhibits root growth and thereby water and nutrient uptake,” explains Joko. “We are also looking at incorporating salt-tolerance and drought-tolerance genes. It’s a step-by-step process where we hope to build tolerance to the multiple stresses that afflict most rice-growing areas throughout Asia and the world.”

Introducing PSTOL1 into maize and sorghum

At EMBRAPA, Claudia is also interested in building up tolerance to multiple stresses and was involved in the project to look for genes similar to PSTOL1 in maize. “As soon as IRRI and JIRCAS had cloned the gene and created markers, we started using the markers to search for the gene in maize, as Jurandir did in sorghum,” she says.

Women farmers in India bring home their sorghum harvest.

Women farmers in India bring home their sorghum harvest.

Finding genes that confer phosphorus-efficiency traits in maize and sorghum has been a more challenging project, according to Leon. “From the rice work, we knew a big part of phosphorus efficiency was to do with root architecture – you want to have shallow horizontal roots instead of roots that grow down, which is often the case in maize and sorghum,” he explains. “This is because there is less accessible phosphorus further down the soil profile.”

Observing root architecture is difficult in ordinary soil, so the team had to develop new ways to visualise the plants’ roots. They grew plants in a transparent nutrient gel, which they then photographed to create three-dimensional images of the root structure.

The team found sorghum and maize varieties that contained genes similar to PSTOL1 in rice, but which also have longer root systems that radiated outwards rather than downwards in gels with higher concentration of aluminium. “These observations helped validate multiple PSTOL1 regions in sorghum and maize, which we’ve been able to develop markers for to help breeders identify these traits more easily,” says Leon.

These markers have successfully been used by sorghum breeders in Brazil and Africa to identify phosphorus-efficient varieties. Maize breeders in both Brazil and Africa are expected to use similar markers to validate their varieties in 2015.

New sorghum varieties prove their worth in the field

Eva Weltzien is one Africa-based sorghum breeder who has benefited from these PSTOL1 and SbMATE markers. Based in Mali at ICRISAT, Eva and her team have been using the markers to select for aluminium-tolerant and phosphorus-efficient varieties and validating their performance in field trials across 29 environments in three countries in West Africa.

She says the markers have helped evolve the way they do their breeding. “Using molecular markers, we are able to identify whether the lines we are breeding have genes that confer the traits that we want,” explains Eva. “It has really revolutionised our breeding program and helped it make great progress in the past three to four years.”

In Mali, sorghum is an important staple crop. It is used to make (a thick porridge), couscous, and local beers. Part of its popularity is its adaptability to various climates – in Mali it is grown in very dry environments as well as in forest/rainforest zones. However, it is widely affected by acidic soils.

Sorghum farmers at work in the field in Mali.

Sorghum farmers at work in the field in Mali.

“Low phosphorus availability is a key problem for farmers on the coast of West Africa, and breeding phosphorus-efficient crops to cope with these conditions has been a main objective of ICRISAT in West Africa for some time,” says Eva.

“We’ve had good results in terms of field trials. We have at least 20 lines we are field testing at the moment, which we selected from 1,100 lines that we tested under high and low phosphorous conditions.” Eva says that some of these lines could be released as new varieties as early as next year.

“Overall, we feel the GCP partnership with EMBRAPA and Cornell is enhancing our capacity here in Mali, and that we are closer to delivering more robust sorghum varieties that will help farmers and feed the ever-growing population in West Africa.”

Leon notes that the work by Eva in Mali and by other African partners in Niger and Kenya is imperative for the research. “Just because plants have these genes, doesn’t mean they will all display aluminium tolerance or phosphorus efficiency. You still need to test and observe for these traits in the field and determine what other factors might affect plants grown in acidic soils.”

One surprising observation that has Leon intrigued is a local sorghum variety with a phosphorus-efficiency gene that is close to where the SbMATE gene resides in the sorghum genome. “This suggests that SbMATE, which aids with aluminium tolerance, may also improve phosphorus efficiency. This means we could use SbMATE markers to look for both phosphorus efficiency and aluminium tolerance,” he says. Leon and Jurandir will continue to validate this result post-GCP.

Working together to improve food security worldwide

GCP’s comparative genomics projects have laid a significant foundation for further research into and breeding for tolerance to multiple plant stresses.

A Kenyan farmer in her maize field.

A Kenyan farmer in her maize field.

“We’re in a golden age of biology where we are learning more and more about the complexities and commonalities of plants, which is allowing us to manipulate them ever so slightly to help them tolerate multiple environmental stresses,” says Leon. “As a geneticist, I am extremely proud to be part of this, particularly seeing the potential impact that the basic research we do in the laboratory can have on crop improvement and the lives of people in poorer countries.”

Although not all projects produced new and improved varieties ready for release, they are well and truly in the pipeline. Each partner institute is committed to work together and source new funding to continue on their quest to produce further products.

“GCP has really installed in us a spirit to see this work through and expand on it,” says Leon. “I mean, we are now working with other countries and institutes to share what we have learnt with them and help them make the discoveries that we have. It’s a credit to GCP for bringing us all together; that was a key to the success of the project. Each partner has brought their expertise to the table – genomics, molecular biology, plant breeding – and it has been great to see the impact filter into Africa and Asia.”

In Kenya, Samuel agrees with Leon’s assessment. “GCP gave us an opportunity to build our expertise and start interacting with the rest of the world,” he says. “But more importantly, it means that we’re contributing to food security in Kenya, and that makes us really proud.”

Although the sun is setting on GCP, work on comparative genomics projects is still in progress, with all parties still working towards delivering important new acid-beating varieties to farmers.

A boy rides his bicycle next to a rice field in the Philippines. With acid soils affecting half the world’s current arable land, acid-beating crop varieties will help farmers feed their families – and the world – into the future.

A boy rides his bicycle next to a rice field in the Philippines. With acid soils affecting half the world’s current arable land, acid-beating crop varieties will help farmers feed their families – and the world – into the future.

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