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Oct 162015
Photo: A Paul-Bossuet/ICRISAT

Pigeonpea farmers in India.

The tagline of the CGIAR Generation Challenge Programme (GCP) is ‘Partnerships in modern crop breeding for food security’. One of GCP’s many rewarding partnerships was with the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).

The Institute was a source of valuable partnerships with highly regarded agricultural scientists and researchers, as well as of germplasm and genetic resources from its gene bank. With assistance from GCP, these resources have enabled scientists and crop breeders throughout Africa, Asia and Latin America to achieve crop improvements for chickpea, groundnut, pearl millet, pigeonpea and sorghum, all of which are staple crops that millions of people depend upon for survival.

“The philosophy of GCP at the start was to tap into and use the genomic recourses we had in our gene banks to develop ICRISAT’s and our partners’ breeding programmes,” says Pooran Gaur, GCP’s Product Delivery Coordinator for chickpeas, and Principal Scientist for chickpea genetics and breeding at ICRISAT.

ICRISAT’s gene bank is a global repository of crop genetic diversity. It contains 123,023 germplasm accessions – in the form of seed samples – assembled from 144 countries, making it one of the largest gene banks in the world.

The collection serves as insurance against genetic loss and as a source of resistance to diseases and pests, tolerance to climatic and other environmental stresses, and improved quality and yield traits for crop breeding.

Pooran says the ultimate goal of the GCP–ICRISAT partnership was to use the resources in the gene bank to develop drought-tolerant varieties that would thrive in semi-arid conditions and to make these varieties available to farmers’ fields within a decade.

Photo: S Kilungu/CCAFS

Harvesting sorghum in Kenya.

Setting a foundation for higher yielding, drought-tolerant chickpeas

Pooran was involved with GCP from its beginning in 2004 and was instrumental in coordinating chickpea projects.


Chickpea harvest, India.

“GCP got things started; it set a foundation for using genomic resources to breed chickpeas,” says Pooran. During Phase I of GCP (2004–2009), ICRISAT was involved in developing reference sets for chickpeas and developing mapping populations for drought-tolerance traits. It also collaborated with 19 other international research organisations to successfully sequence the chickpea genome in 2013 – a major breakthrough that paved the way for the development of even more superior chickpea varieties to transform production in semi-arid environments.

The International Chickpea Genome Sequencing Consortium, led by ICRISAT and partly funded by GCP, identified more than 28,000 genes and several million genetic markers. Pooran says these are expected to illuminate important genetic traits that may enhance new varieties.

The trait of most interest to many chickpea breeders is drought tolerance. In recent years, droughts in the south of India, the largest producer of chickpeas, have reduced yields to less than one tonne per hectare. Droughts have also diminished chickpea yields in Ethiopia and Kenya, Africa’s largest chickpea producers and exporters to India. While total global production of chickpeas is around 8.6 million tonnes per year, drought causes losses of around 3.7 million tonnes worldwide.


Putting it to the test: Rajeev Varshney (left, see below) and Pooran Gaur (right) inspecting a chickpea field trial.

Pooran says the foundation work supported by GCP was particularly important for identifying drought-tolerance traits. “We had identified plants with early maturing traits. This allowed us to develop chickpea varieties that have more chance of escaping drought when cereal farmers produce a fast-growing crop in between the harvest and planting of their main crops,” he says.

New varieties that grow and develop more quickly are expected to play a key role in expanding the area suitable for chickpeas into new niches where the available crop-growing seasons are shorter.

“In southern India now we are already seeing these varieties growing well, and their yield is very high,” says Pooran. “In fact, productivity has increased in the south by about seven to eight times in the last 10–12 years.”

Developing capacity by involving partners in Kenya and Ethiopia

Photo: GCP

Monitoring the water use of chickpea plants in experiments at Egerton University, Njoro, Kenya.

As part of GCP’s Tropical Legumes I project (TLI), incorporated within its Legume Research Initiative (RI), ICRISAT partnered with Egerton University in Kenya and the Ethiopian Institute of Agricultural Research (EIAR) to share breeding skills and resources to produce higher yielding, drought-tolerant chickpea varieties.

“When we first started working on this project in mid-2007, our breeding programme was very weak,” says Paul Kimurto of the Faculty of Agriculture at Egerton University, who was Lead Scientist for chickpea research in the TLI project. “We have since accumulated a lot of germplasm, a chickpea reference set and a mapping population, all of which have greatly boosted our breeding programme.”

Paul says that with this increased capacity, his team in Kenya had released six new varieties of chickpea in the five years prior to GCP’s close at the end of 2014, and were expecting more to be ready within in the next three years.

In fields across Ethiopia, meanwhile, the introduction of new varieties has already brought a dramatic increase in productivity, with yields doubling in recent years, according to Asnake Fikre, Crop Research Directorate Director for EIAR.

Varieties like the large-seeded and high-valued kabuli have presented new opportunities for farmers to earn extra income through the export industry, and indeed chickpea exports from eastern Africa have substantially increased since 2001. This has transformed Ethiopia’s chickpeas from simple subsistence crop to one of great commercial significance.

Photo: S Sridharan/ICRISAT

This chickpea seller in Ethiopia says that kabuli varieties are becoming more popular.

Decoding pigeonpea genome

Two years prior to the decoding of the chickpea genome, GCP’s Director Jean-Marcel Ribaut announced that a six-year, GCP-funded collaboration led by ICRISAT had already sequenced almost three-quarters of the pigeonpea genome.

“This will have significant impact on resource-poor communities in the semi-arid regions, because they will have the opportunity to improve their livelihoods and increase food availability,” Jean-Marcel stated in January 2012.

Pigeonpea, the grains of which make a highly nutritious and protein-rich food, is a hardy and drought-tolerant crop. It is grown in the semi-arid tropics and subtropics of Asia, Africa, the Americas and the Caribbean. This crop’s prolific seed production and tolerance to drought help reduce farmers’ vulnerability to potential food shortages during dry periods.

Photo: B Sreeram/ICRISAT

A pigeonpea farmer in his field in India.

The collaborative project brought together 12 participating institutes operating under the umbrella of the International Initiative for Pigeonpea Genomics. The initiative was led by Rajeev K Varshney, GCP’s Genomics Theme Leader and Director of the Center of Excellence in Genomics at ICRISAT. Other participants included BGI in Shenzhen, China; four universities; and five other advanced research entities, both private and public. The Plant Genome Research Program of the National Science Foundation, USA, also funded part of this research.

“We were able to assemble over 70 percent of the genome. This was sufficient to enable us to change breeding approaches for pigeonpea,” says Rajeev. “That is, we can now combine conventional and molecular breeding methods – something we couldn’t do as well before – and access enough genes to create many new pigeonpea varieties that will effectively help improve the food security and livelihoods of resource-poor communities.”

Pigeonpea breeders are now able to use markers for genetic mapping and trait identification, marker-assisted selection, marker-assisted recurrent selection and genomic selection. These techniques, Rajeev says, “considerably cut breeding time by doing away with several cropping cycles. This means new varieties reach dryland areas of Africa and Asia more quickly, thus improving and increasing the sustainability of food production systems in these regions.”

Several genes, unique to pigeonpea, were also identified for drought tolerance by the project. Future research may find ways of transferring these genes to other legumes in the same family – such as soybean, cowpea and common bean – helping these crops also become more drought tolerant. This would be a significant asset in view of the increasingly drier climates in these crops’ production areas.

“We cannot help but agree with William Dar, Director General of ICRISAT, who observed that the ‘mapping of the pigeonpea genome is a breakthrough that could not have come at a better time’,” says Jean-Marcel.


East African farmers inspect pigeonpea at flowering time.

Securing income-generating groundnut crops in Africa

Groundnut, otherwise known as peanut, is one of ICRISAT’s mandate crops. Groundnuts provide a key source of nutrition for Africa’s farming families and have the potential to sustain a strong African export industry in future.

“The groundnut is one of the most important income-generating crops for my country and other countries in East Africa,” says Patrick Okori, who is a groundnut breeder and Principal Scientist with ICRISAT in Malawi and who was 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

It is the same in West Africa, according to groundnut breeder Issa Faye from the Institut Sénégalais de Recherches Agricoles (ISRA), 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 groundnut in West Africa.”

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, including those from ICRISAT, 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.

Photo: S Sridharan/ICRISAT

Drying groundnut harvest, Mozambique.

“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 science

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.

Supporting key crops in West Africa

Photo: N Palmer/CIAT

Harvested pearl millet and sorghum in Ghana.

With a focus on the semi-arid tropics, ICRISAT has been working closely with partners for 30 years to improve rainfed farming systems in West Africa. One sorghum researcher who has been working on the ground with local partners in Mali since 1998 is Eva Weltzien-Rattunde. She is an ICRISAT Principal Scientist in sorghum breeding and genetic resources, based in Mali, and was Principal Investigator for GCP’s Sorghum Research Initiative.

Eva and her team collaborated with local researchers at Mali’s Institut d’Economie Rurale (IER) and France’s Centre de coopération internationale en recherche agronomique pour le développement (CIRAD; Agricultural Research for Development) on a project to test a novel molecular-breeding approach: backcross nested association mapping (BCNAM). Eva says this method has the potential to halve the time it takes to develop local sorghum varieties with improved yield and adaptability to poor soil fertility conditions.

In another project, under GCP’s Comparative Genomics Research Initiative, Eva and her team are using molecular markers developed through the RI 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.

“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 2015.

Ibrahima Sissoko, a data curator working with Eva’s team at ICRISAT in Mali, also adds that the collaborations and involvement with GCP have increased his and other developing country partners’ capacity in data management and statistical analysis, as well as helping to expand their network. “I can get help from other members of my sorghum community,” he says.

In summing up, Eva says: “Overall, we feel the GCP partnerships are 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.”

Photo: A Paul-Bossuet/ICRISAT

Enjoying a tasty dish of sorghum.

Tom Hash, millet breeder and Principal Scientist at ICRISAT and GCP Principal Investigator for millet, shares Eva’s sentiments on GCP and the impact it is having in West Africa.

Between 2005 and 2007, GCP invested in genetic research for millet, which is the sixth most important cereal crop globally and a staple food (along with sorghum) in Burkina Faso, Chad, Eritrea, Mali, Niger, northern Nigeria, Senegal and Sudan.

With financial support from GCP, and drawing on lessons learnt from parallel GCP genetic research, including in sorghum and chickpea, ICRISAT was able to mine its considerable pearl millet genetic resources for desirable traits.

Hari D Upadhyaya, Principal Scientist and Head of Genebank at ICRISAT in India, led this task to develop and genotype a ‘composite collection’ of pearl millet. The team created a selection that strategically reduced the 21,594 accessions in the gene bank down to just 1,021. This collection includes lines developed at ICRISAT and material from other sources, with a range of valuable traits including tolerance to drought, heat and soil salinity and resistance to blast, downy mildew, ergot, rust and smut, and even resistance to multiple diseases.

The team then used molecular markers to fingerprint the DNA of plants grown from the collection.

“GCP supported collaboration with CIRAD, and our pearl millet breeding teams learnt how to do marker-based genetic diversity analysis,” says Tom. “This work, combined with the genomic resources work, did make some significant contributions to pearl millet research.”

Over 100 new varieties of pearl millet have recently been developed and released in Africa by the African Centre for Crop Improvement in South Africa, another developing country partner of ICRISAT and GCP. Tom says the initial genetic research was pivotal to this happening.

Photo: N Palmer/CIAT

A Ghanaian farmer examines his pearl millet harvest.

From poverty to prosperity through partnerships

Patrick Okori says that GCP has enabled his organisation to make a much stronger contribution to the quality of science.

“Prior to GCP, ICRISAT was already one of the big investors in legume research, because that was its mandate. The arrival of GCP, however, expanded the number of partners that ICRISAT had, both locally and globally, through the resources, strategic meetings and partnership arrangements that GCP provided as a broad platform for engaging in genomic research and the life sciences.”

This expansion of ICRISAT, facilitated by GCP, also enabled researchers from across the world and in diverse fields to interact in ways they had never had the opportunity to before, says Vincent Vadez.

“GCP has allowed me to make contact with people working on other legumes, for example,” he says. “It has allowed us to test hypotheses in other related crops, and we’ve generated quite a bit of good science from that.”

Pooran Gaur has had a similar experience with his chickpea research at ICRISAT.

“GCP provided the first opportunity for us to work with the bean and cowpea groups, learning from each other. That cross-learning from other crops really helped us. You learn many things working together, and I think we have developed a good relationship, a good community for legumes now.”

This community environment has made the best use of an unusual variety of skills, knowledge and resources, agrees Rajeev Varshney.

“It brought together people from all kinds of scientific disciplines – from genomics, bioinformatics, biology, molecular biology and so on,” he says. “Such a pooling of complementary expertise and resources made great achievements possible.”

More links

Photo: A Paul-Bossuet/ICRISAT

Man and beast team up to transport chickpeas in Ethiopia.


Oct 122015


Photo: One Acre Fund/Flickr (Creative Commons)

A Kenyan farmer harvesting her maize.

“The map of Kenya’s maize-growing regions mirrors the map of the nation’s acid soils.”

So says Dickson Ligeyo, senior research officer at the Kenya Agricultural and Livestock Research Organisation (KALRO; formerly the Kenya Agricultural Research Institute, or KARI), who believes this paints a sombre picture for his country’s maize farmers.

Maize is a staple crop for Kenyans, with 90 percent of the population depending on it for food. However, acid soils cause yield losses of 17–50 percent across the nation.

Soil acidity is a major environmental and economic concern in many more countries around the world. The availability of nutrients in soil is affected by pH, so acid conditions make it harder for plants to get a balanced diet. High acidity causes two major problems: perilously low levels of phosphorus and toxically high levels of aluminium. Aluminium toxicity affects 38 percent of farmland in Southeast Asia, 31 percent in Latin America and 20 percent in East Asia, sub-Saharan Africa and North America.

Aluminium toxicity in soil comes close to rivalling drought as a food-security threat in critical tropical food-producing regions. By damaging roots, acid soils deprive plants of the nutrients and water they need to grow – a particularly bitter effect when water is scarce.

Maize, meanwhile, is one of the most economically important food crops worldwide. It is grown in virtually every country in the world, and it is a staple food for more than 1.2 billion people in developing countries across sub-Saharan Africa and Latin America. In many cultures it is consumed primarily as porridge: polenta in Italy; angu in Brazil; and isitshwala, nshima, pap, posho,sadza or ugali in Africa.

Photo: Allison Mickel/Flickr (Creative Commons)

Ugali, a stiff maize porridge that is a staple dish across East Africa, being prepared in Tanzania.

Maize is also a staple food for animals reared for meat, eggs and dairy products. Around 60 percent of global maize production is used for animal feed.

The world demand for maize is increasing at the same time as global populations burgeon and climate changes. Therefore, improving the ability of maize to withstand acid soils and produce higher yields with less reliable rainfall is paramount. This is why the CGIAR Generation Challenge Programme (GCP) invested almost USD 12.5 million into maize research between 2004 and 2014.

GCP’s goal was to facilitate the use of genetic diversity and advanced plant science to improve food security in developing countries through the breeding of ‘super’ crops – including maize – able to tolerate drought and poor soils and resist diseases.

 By weight, more maize is produced each year than any other grain: global production is more than 850 million tonnes. Maize production is increasing at twice the annual rate of rice and three times that of wheat. In 2020, demand for maize in developing countries alone is expected to exceed 500 million tonnes and will surpass the demand for both rice and wheat.  This projected rapid increase in demand is mainly because maize is the grain of choice to feed animals being reared for meet – but it is placing strain on the supply of maize for poor human consumers. Demand for maize as feed for poultry and pigs is growing, particularly in East and Southeast Asia, as an ever-increasing number of people in Asia consume meat. In some areas of Asia, maize is already displacing sorghum and rice. Acreage allocated to maize production in South and Southeast Asia has been expanding by 2.2 percent annually since 2001. In its processed form, maize is also used for biofuel (ethanol), and the starch and sugars from maize end up in beer, ice cream, syrup, shoe polish, glue, fireworks, ink, batteries, mustard, cosmetics, aspirin and paint.

Researchers take on the double whammy of acid soils and drought

Part of successfully breeding higher-yielding drought-tolerant maize varieties involves improving plant genetics for acid soils. In these soils, aluminium toxicity inhibits root growth, reducing the amount of water and nutrients that the plant can absorb and compounding the effects of drought.

Improving plant root development for aluminium tolerance and phosphorous efficiency can therefore have the positive side effect of higher plant yield when water is limited.

Photo: A Wangalachi/CIMMYT

A farmer in Tanzania shows the effects of drought on her maize crop. The maize ears are undersized with few grains.

Although plant breeders have exploited the considerable variation in aluminium tolerance between different maize varieties for many years, aluminium toxicity has been a significant but poorly understood component of plant genetics. It is a particularly complex trait in maize that involves multiple genes and physiological mechanisms.

The solution is to take stock of what maize germplasm is available worldwide, characterise it, clone the sought-after genes and implement new breeding methods to increase diversity and genetic stocks.

Scientists join hands to unravel maize complexity

Scientists from the International Maize and Wheat Improvement Center (CIMMYT) and the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) got their heads together between 2005 and 2008 to itemise what maize stocks were available.

Marilyn Warburton, then a molecular geneticist at CIMMYT, led this GCP-funded project. Her goal was to discover how all the genetic diversity in maize gene-bank collections around the globe might be used for practical plant improvement. She first gathered samples from gene banks all over the world, including those of CIMMYT and the International Institute of Tropical Agriculture (IITA). Scientists from developing country research centres in China, India, Indonesia, Kenya, Nigeria, Thailand and Vietnam also contributed by supplying DNA from their local varieties.

Photo: X Fonseca/CIMMYT

Maize diversity.

Researchers then used molecular markers and a bulk fingerprinting method – which Marilyn was instrumental in developing – for three purposes: to characterise the structure of maize populations, to better understand how maize migrated across the world, and to complete the global picture of maize biodiversity. Scientists were also using markers to search for new genes associated with desirable traits.

Allen Oppong, a maize pathologist and breeder from Ghana’s Crops Research Institute (CRI), of the Council for Scientific and Industrial Research, was supported by GCP from 2007 to 2010 to characterise Ghana’s maize germplasm. Trained in using the fingerprinting technique, Allen was able to identify distinctly different maize germplasm in the north of Ghana (with its dry savanna landscape) and in the south (with its high rainfall). He also identified mixed germplasm, which he says demonstrates that plant germplasm often finds its way to places where it is not suitable for optimal yield and productivity. Maize yields across the country are low.

Stocktaking a world’s worth of maize for GCP was a challenge, but not the only one, according to Marilyn. “In the first year it was hard to see how all the different partners would work together. Data analysis and storage was the hardest; everyone seemed to have their own idea about how the data could be stored, accessed and analysed best.

“The science was also evolving, even as we were working, so you could choose one way to sequence or genotype your data, and before you were even done with the project, a better way would be available,” she recalls.

Photo: N Palmer/CIAT

Maize ears drying in Ghana.

Comparing genes: sorghum gene paves way for maize aluminium tolerance

In parallel to Marilyn’s work, scientists at the Brazilian Corporation of Agricultural Research (EMBRAPA) had already been advancing research on plant genetics for acid soils and the effects of aluminium toxicity on sorghum – spurred on by the fact that almost 70 percent of Brazil’s arable land is made up of acid soils.

What was of particular interest to GCP in 2004 was that the Brazilians, together with researchers at Cornell University in the USA, had recently mapped and identified the major sorghum aluminium tolerance locus AltSB, and were working on isolating the major gene within it with a view to cloning it. Major genes were known to control aluminium tolerance in sorghum, wheat and barley and produce good yields in soils that had high levels of aluminium. The gene had also been found in rape and rye.

GCP embraced the opportunity to fund more of this work with a view to speeding up the development of maize – as well as sorghum and rice – germplasm that can withstand the double whammy of acid soils and drought.

Photo: L Kochian

Maize trials in the field at EMBRAPA. The maize plants on the left are aluminium-tolerant and so able to withstand acid soils, while those on the right are not.

Leon Kochian, Director of the Robert W Holley Center for Agriculture and Health, United States Department of Agriculture – Agricultural Research Service and Professor at Cornell University, was a Principal Investigator for various GCP research projects investigating how to improve grain yields of crops grown in acid soils. “GCP was interested in our work because we were working with such critical crops,” he says.

“The idea was to use discoveries made in the first half of the GCP’s 10-year programme – use comparative genomics to look into genes of rice and maize to see if we can see relations in those genes – and once you’ve cloned a gene, it is easier to find a gene that can work for other crops.”

The intensity of GCP-supported maize research shifted up a gear in 2007, after the team led by Jurandir Magalhães, research scientist in molecular genetics and genomics of maize and sorghum at EMBRAPA, used positional cloning to identify the major sorghum aluminium tolerance gene SbMATE responsible for the AltSB aluminium tolerance locus. The team comprised researchers from EMBRAPA, Cornell, the Japan International Research Center for Agricultural Sciences (JIRCAS) and Moi University in Kenya.

By combing the maize genome searching for a similar gene to sorghum’s SbMATE, Jurandir’s EMBRAPA colleague Claudia Guimarães and a team of GCP-supported scientists discovered the maize aluminium tolerance gene ZmMATE1. High expression of this gene, first observed in maize lines with three copies of ZmMATE1, has been shown to increase aluminium tolerance.  ZmMATE1 improves grain yields in acid soil by up to one tonne per hectare when introgressed in an aluminium-sensitive line.

Photos: 1 – V Alves ; 2 – F Mendes; both edited by C Guimarães

The genetic region, or locus, containing the ZmMATE1 aluminium tolerance gene is known as qALT6. Photo 1 shows a rhyzobox containing two layers of soil: a corrected top-soil and lower soils with 15 percent aluminium saturation. On the right, near-isogenic lines (NILs) introgressed with qALT6 show deeper roots and longer secondary roots in the acidic lower soil, whereas on the left the maize line without qALT6, L53, shows roots mainly confined to the corrected top soil. Photo 2 shows maize ears from lines without qALT6 (above) and with qALT6 (below); the lines with qALT6 maintain their size and quality even under high aluminium levels of 40 percent aluminium saturation.

The outcomes of these GCP-supported research projects provided the basic materials, such as molecular markers and donor sources of the positive alleles, for molecular-breeding programmes focusing on improving maize production and stability on acid soils in Latin America, Africa and other developing regions.

Kenya deploys powerful maize genes

One of those researchers crucial to achieving impact in GCP’s work in maize was Samuel (Sam) Gudu of Moi University, Kenya. From 2010 he was the Principal Investigator for GCP’s project on using marker-assisted backcrossing (MABC) to improve aluminium tolerance and phosphorous efficiency in maize in Kenya. This project combined molecular and conventional breeding approaches to speed up the development of maize varieties adapted to the acid soils of Africa, and was closely connected to the other GCP comparative genomics projects in maize and sorghum.

MABC is a type of marker-assisted selection (see box), which Sam’s team – including Dickson Ligeyo of KALRO – used to combine new molecular materials developed through GCP with Kenyan varieties. They have thus been able to significantly advance the breeding of maize varieties suitable for soils in Kenya and other African countries.

Marker-assisted selection helps breeders like Sam Gudu more quickly develop plants that have desirable genes. When two plants are sexually crossed, both positive and negative traits are inherited. The ongoing process of selecting plants with more desirable traits and crossing them with other plants to transfer and combine such traits takes many years using conventional breeding techniques, as each generation of plants must be grown to maturity and phenotyped – that is, the observable characteristics of the plants must be measured to determine which plants might contain genes for valuable traits.   By using molecular markers that are known to be linked to useful genes such as ZmMATE1, breeders can easily test plant materials to see whether or not these genes 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. Marker-assisted selection therefore reduces the number of years it takes to breed plant varieties with desired traits.

Maize and Comparative Genomics were two of seven Research Initiatives (RIs) where GCP concentrated on advancing researchers’ and breeders’ skills and resources in developing countries. Through this work, scientists have been able to characterise maize germplasm using improved trait observation and characterisation methods (phenotyping), implement molecular-breeding programmes, enhance strategic data management and build local human and infrastructure capacity.

The ultimate goal of the international research collaboration on comparative genomics in maize was to improve maize yields grown on acidic soils under drought conditions in Kenya and other African countries, as well as in Latin America. Seven institutes partnered up to for the comparative genomics research: Moi University, KALRO, EMBRAPA, Cornell University, the United States Department of Agriculture (USDA), JIRCAS and the International Rice Research Institute (IRRI).

“Before funding by GCP, we were mainly working on maize to develop breeding products resistant to disease and with increased yield,” says Sam. “At that time we had not known that soil acidity was a major problem in the parts of Kenya where we grow maize and sorghum. GCP knew that soil acidity could limit yields, so in the work with GCP we managed to characterise most of our acid soils. We now know that it was one of the major problems for limiting the yield of maize and sorghum.

“The relationship to EMBRAPA and Cornell University is one of the most important links we have. We developed material much faster through our collaboration with our colleagues in the advanced labs. I can see that post-GCP we will still want to communicate and interact with our colleagues in Brazil and the USA to enable us to continue to identify molecular materials that we discover,” he says. Sam and other maize researchers across Kenya, including Dickson, have since developed inbred, hybrid and synthetic varieties with improved aluminium tolerance for acid soils, which are now available for African farmers.

Photo: N Palmer/CIAT

A Kenyan maize farmer.

“We crossed them [the new genes identified to have aluminium tolerance] with our local material to produce the materials we required for our conditions,” says Sam.

“The potential for aluminium-tolerant and phosphorous-efficient material across Africa is great. I know that in Ethiopia, aluminium toxicity from acid soil is a problem. It is also a major problem in Tanzania. It is a major problem in South Africa and a major problem in Kenya. So our breeding work, which is starting now to produce genetic materials that can be used directly, or could be developed even further in these other countries, is laying the foundation for maize improvement in acid soils.”

Sam is very proud of the work: “Several times I have felt accomplishment, because we identified material for Kenya for the first time. No one else was working on phosphorous efficiency or aluminium tolerance, and we have come up with materials that have been tested and have become varieties. It made me feel that we’re contributing to food security in Kenya.”

Photo: N Palmer/CIAT

Maize grain for sale.

Maize for meat: GCP’s advances in maize genetics help feed Asia’s new appetites

Reaping from the substantial advances in maize genetics and breeding, researchers in Asia were also able to enhance Asian maize genetic resources.

Photo: D Mowbray/CIMMYT

A pig roots among maize ears on a small farm in Nepal.

Bindiganavile Vivek, a senior maize breeder for CIMMYT based in India, has been working with GCP since 2008 on improving drought tolerance in maize, especially for Asia, for two reasons: unrelenting droughts and a staggering growth the importance of maize as a feedstock. This work was funded by GCP as part of its Maize Research Initiative.

“People’s diets across Asia changed after government policies changed in the 1990s. We had a more free market economy, and along with that came more money that people could spend. That prompted a shift towards a non vegetarian diet,” Vivek recounts.

“Maize, being the number one feed crop of the world, started to come into demand. From the year 2000 up to now, the growing area of maize across Asia has been increasing by about two percent every year. That’s a phenomenal increase. It’s been replacing other crops – sorghum and rice. There’s more and more demand.

“Seventy percent of the maize that is produced in Asia is used as feed. And 70 percent of that feed is poultry feed.”

In Vietnam, for example, the government is actively promoting the expansion of maize acreage, again displacing rice. Other Asian nations involved in the push for maize include China, Indonesia and The Philippines.

Photo: A Erlangga/CIFOR

A farmer in Indonesia transports his maize harvest by motorcycle.

The problem with this growth is that 80 percent of the 19 million hectares of maize in South and Southeast Asia relies on rain as its only source of water, so is prone to drought: “Wherever you are, you cannot escape drought,” says Vivek. And resource-poor farmers have limited access to improved maize products or hybrids appropriate for their situation.

Vivek’s research for GCP focused on the development – using marker-assisted breeding methods, specifically marker-assisted recurrent selection (MARS) – of new drought-tolerant maize adapted to many countries in Asia. His goal was to transfer the highest expression of drought tolerance in maize into elite well-adapted Asian lines targeted at drought-prone or water-constrained environments.

Asia’s existing maize varieties had no history of breeding for drought tolerance, only for disease resistance. To make a plant drought tolerant, many genes have to be incorporated into a new variety. So Vivek asked: “How do you address the increasing demand for maize that meets the drought-tolerance issue?”

The recent work on advancing maize genetics for acid soils in the African and Brazilian GCP projects meant it was a golden opportunity for Vivek to reap some of the new genetic resources.

“This was a good opportunity to use African germplasm, bring it into India and cross it to some Asia-adapted material,” he says.

Photo: E Phipps/CIMMYT

Stored maize ears hanging in long bunches outside a house in China.

A key issue Vivek faced, however, was that most African maize varieties are white, and most Asian maize varieties are yellow. “You cannot directly deploy what you breed in Africa into Asia,” Vivek says. “Plus, there’s so much difference in the environments [between Africa and Asia] and maize is very responsive to its environment.”

The advances in marker-assisted breeding since the inception of GCP contributed significantly towards the success of Vivek’s team.

“In collaboration with GCP, IITA, Cornell University and Monsanto, CIMMYT has initiated the largest public sector MARS breeding approach in the world,” says Vivek.

The outcome is good: “We now have some early-generation, yellow, drought-tolerant inbred germplasm and lines suitable for Asia.

“GCP gave us a good start. We now need to expand and build on this,” says Vivek.

GCP’s supported work laid the foundation for other CIMMYT projects, such as the Affordable, Accessible, Asian Drought-Tolerant Maize project funded by the Syngenta Foundation for Sustainable Agriculture. This project is developing yet more germplasm with drought tolerance.

A better picture: GCP brightens maize research

Dickson Ligeyo’s worries of a stormy future for Kenya’s maize production have lifted over the 10 years of GCP. At the end of 2014, Kenya had two new varieties that were in the final stage of testing in the national performance trials before being released to farmers.

“There is a brighter picture for Kenya’s maize production since we have acquired acid-tolerant germplasm from Brazil, which we are using in our breeding programmes,” Dickson says.

In West Africa, researchers are also revelling in the opportunity they have been given to help enhance local yields in the face of a changing climate. “My institute benefited from GCP not only in terms of human resource development, but also in provision of some basic equipment for field phenotyping and some laboratory equipment,” says Allen Oppong in Ghana.

“Through the support of GCP, I was able to characterise maize landraces found in Ghana using the bulk fingerprinting technique. This work has been published and I think it’s useful information for maize breeding in Ghana – and possibly other parts of the world.”

The main challenge now for breeders, according to Allen, is getting the new varieties out to farmers: “Most people don’t like change. The new varieties are higher yielding, disease resistant, nutritious – all good qualities. But the challenge is demonstrating to farmers that these materials are better than what they have.”


This Kenyan farmer is very happy with his healthy maize crop, grown using an improved variety during a period of drought.

Certainly GCP has strengthened the capacity of researchers across Africa, Asia and Latin America, training researchers in maize breeding, data management, statistics, trial evaluations and phenotyping. The training has been geared so that scientists in developed countries can use genetic diversity and advanced plant science to improve crops for greater food security in the developing world.

Elliot Tembo, a maize breeder with the private sector in sub-Saharan Africa says: “As a breeder and a student, I have been exposed to new breeding tools through GCP. Before my involvement, I was literally blind in the use of molecular tools. Now, I am no longer relying only on pedigree data – which is not always reliable – to classify germplasm.”

Allen agrees: “GCP has had tremendous impact on my life as a researcher. The capacity-building programme supported my training in marker-assisted selection training at CIMMYT in Mexico. This training exposed me to modern techniques in plant breeding and genomics. Similarly, it built my confidence and work efficiency.”

There is no doubt that GCP research has brightened the picture for maize research and development where it is most needed: with researchers in developing countries where poor farmers and communities rely on maize as their staple food and main crop.

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Photo: N Palmer/CIAT

A farmer displays maize harvested on his farm in Laos.

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


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.