Little did some of Ghana’s crop researchers know back in 2007 that they would be cultivating not just their plants but also themselves over the following seven years.
“When you see one person being trained and then another person being trained, it doesn’t mean much. But when you put all the numbers together and they see themselves as a force, as a team, I think that’s where new strength lies for our African researchers,” reflects Elizabeth Parkes on the impacts of the CGIAR Generation Challenge Programme (GCP).
“Wherever I go, whatever opportunity I have, I refer back to GCP and its capacity-building work. You see, it’s good to release new plant varieties, but it’s also good to release people,” she says.
The internationally funded GCP set out to enhance the local plant-breeding capabilities of people like Elizabeth, and so help developing nations meet ever-growing demands for food in the face of climate change and worsening drought conditions, the threat of crop disease, and other pressures.
Scientists at the Crops Research Institute (CRI) work to improve crop production in Ghana and so ensure national food security and decent livelihoods for people like this Ghanaian cassava farmer.
This has meant empowering scientists with cutting-edge tools and knowledge, as well as overcoming some surprisingly down-to-earth obstacles.
“One thing that really energises me,” enthuses GCP Consultant Hannibal Muhtar, “is seeing people understand why they need to do the work and being given the chance to do the how.”
Hannibal, under his GCP remit, was asked to visit the research sites of GCP-funded projects at research centres and stations across Africa, to identify those where effective research might be hindered by significant gaps in three fundamental areas: infrastructure, equipment and support services. He selected 19 target research sites, in Burkina Faso, Ethiopia, Ghana, Kenya, Mali, Niger, Nigeria and Tanzania. Two of these were in Ghana, namely the CRI research sites at Kumasi and Tamale.
The mission of CRI is to ensure high and sustainable crop productivity and food security in Ghana through the development and dissemination of environmentally sound technologies. Its research areas are broad and include maize, rice, cowpeas, soybeans, groundnuts, cassava, yams, cocoyams, sweetpotatoes, plantains and bananas.
In developing countries like Ghana that the obstacles to achieving research objectives are often quite mundane in nature: a faulty weather station, a lack of irrigation systems, or fields ravaged by weeds or drainage problems and in dire need of rehabilitation. Yet such factors compromise brilliant research.
Even a simple lack of fencing commonly results not only in equipment being stolen, but also in precious experimental crops being stomped on by roaming cattle and wild animals such as boars, monkeys, hippopotamuses and hyenas; this also poses a serious threat to the safety of field staff.
“The real challenge lies not in the science, but rather in the real nuts and bolts of getting the work done in local field conditions,” Hannibal explains.
He says: “If GCP had not invested in research support infrastructure and services, then their investment in research would have been in vain. Tools and services must be in place as and when needed, and in good working order. Tractors must be able to plough when they should plough.”
Cassava chips on sale in a Ghanaian market.
Ghana gains a new centre of excellence
Elizabeth is one of more than 10 researchers from Ghana who gained their PhDs via GCP-funded research projects. They were given the opportunity to travel to international research laboratories to learn the latest research methods, train in genotyping and establish contacts with leading scientific minds.
“They [GCP] have made us attractive for others to collaborate with,” says Elizabeth.
“GCP gave you the keys to solving your own problems; it put structures in place so that knowledge learnt abroad could be transferred and applied at home.
“Before GCP we really struggled, but now everybody wants to have training in Ghana. Everybody wants to have something to do with us, and I will always say thank you to GCP for that, for making us attractive as researchers,” Elizabeth says.
At the outset of the Programme, Elizabeth was learning how to breed new cassava varieties suitable for African soils. She worked with scientists from IITA in Nigeria to use genetic resources (germplasm) from South America, where cassava originates, to integrate the CMD2 gene into local germplasm using molecular breeding. CMD2 gives cassava resistance to the devastating cassava mosaic disease, which slowly shrivels and yellows leaves and roots, destroying crop yields.
Elizabeth Parkes poses with a sturdy and nutritious harvest of cassava roots.
Cassava is a lifeline for African people, and is a particularly important staple food for poorer farmers. More cassava is produced in Africa than any other crop, according to 2012 figures from the Food and Agriculture Organization of the United Nations. It is grown by nearly every farming family in sub-Saharan Africa, supplying about a third of people’s daily energy intake in the region. This makes cassava mosaic disease a potential disaster, and makes effectively breeding improved varieties an activity with real impact.
“We started out doing low-cost marker-assisted selection, for which we had some grants. Someway, somehow, the government got interested and brought in more resources. So together we started a small biotech lab. Now this lab has become the Centre of Excellence for West African productivity,” says Elizabeth.
“I have attended three GCP Annual Research Meetings, and I have won awards for my posters. This greatly boosted my confidence,” says Elizabeth. She also continues to be an active member of the Cassava Community of Practice – founded by GCP and now hosted by the Integrated Breeding Platform (IBP) – which facilitates and supports the integration of marker-assisted selection into cassava breeding. All this has accelerated Elizabeth’s quest to produce and disseminate farmer-preferred cassava varieties that are resistant to pests and diseases.
“We are all forever grateful to GCP and its funders. GCP has had a huge impact on research in Ghana, especially for cassava, rice, maize and yam. All the agricultural research institutes and individual scientists who came into contact with GCP have been fundamentally transformed.”
Capacity building à la carte a real ‘life changer’
For Allen Oppong, a maize pathologist at CRI, GCP was a life changer too: “Indeed, I am very grateful to GCP for making me what I am today.”
Allen’s first experience of GCP was in 2007, when he won a Capacity building à la carte grant for research into characterising locally adapted maize varieties. During the project he travelled to international research meetings and received training in marker-assisted selection in advanced laboratories.
Infrastructure improvements funded by GCP also came at a critical time for Allen. There was a drought, which, without the irrigation systems provided through the Programme, would have meant a much longer research process.
Even without drought, these kinds of improvements can dramatically speed up breeding, as Hannibal explains: “By providing glasshouses or the capacity to irrigate in the dry season, we are enabling breeders to accelerate their breeding cycles, so that they can work all year round rather than having to wait until the rain comes.”
“Through the support of GCP,” Allen recalls, “I was able to characterise maize varieties 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.”
One of the biggest challenges that Allen experienced during his GCP work was getting farmers to try the new varieties that are being developed.
“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.
A Ghanaian farmer holds a just-harvested maize ear.
“You can have very good material that has all these attributes, but if the farmer doesn’t have access to it, then how can he know the attributes that you are talking about? How can he see it when it is in your research station?”
Ghanaian farmers generally select maize varieties for their adaptation to specific local environments. But as Allen explains, average maize yields in Ghana, at 1–1.5 tonnes per hectare, are well below the global average of 5.2 tonnes per hectare.
Allen is looking forward optimistically to this next stage. “We have the capacity to more than double what we are producing now. The possibility is there, as long as farmers adopt the good materials.”
A ‘kick-start’ for plant science and for people
The catalytic effect of international funding programmes like GCP on small research laboratories in developing countries is often underestimated.
“We got GCP support to kick-start molecular biology research activities,” says Marian Quain, a senior research scientist at CRI. “It provided us with laboratory chemicals, reagent and equipment. My lab also received funding under the Genotyping Support Service initiative to characterise hundreds of sweetpotato, yam and cassava accessions.
“This support from GCP contributed immensely to transforming the lab.”
Ruth Prempeh – CRI researcher who was able to achieve her PhD with GCP support – hard at work collecting data in the field.
Funding injections can kick-start careers for young scientists too. In 2009, Ruth Prempeh received funding for her PhD, Genetic analysis of postharvest physiological deterioration in cassava (Manihot esculenta Crantz) storage roots, which was completed in 2013.
“From my thesis, l have prepared three manuscripts for publication. I have also had the opportunity to attend the three-year Integrated Breeding Multiyear Course, during which l acquired knowledge and skills in data analysis, interpretation and management and also in using modern technologies for crop improvement,” says Ruth.
“This has been very useful and has really had an impact on my career, making me what l am today. With this, l know l have a great future and I believe l will achieve great things. I am really proud to have been associated with GCP and very grateful for the opportunity.”
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.
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.
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.
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.
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.
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.
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.
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.”
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.
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.
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.
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.”
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.
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.
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.
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.
Elizabeth Parkes grew up in Ghana as the youngest child and only girl in a middle-class family of nine children. Through visiting poor communities with her family, she began from an early age to build her understanding of the lives of resource-poor families in this part of West Africa and their need for reliable and nutritious food.
She also knows first-hand the important role women play on a farm and in a family. “Rural families are held together by women, so if you are able to change their lot, you can make a real mark,” says Elizabeth.
It was this sense of social conscience that drew her to a career in agricultural research: “My father, a Regional Education Officer, was not very amused; he thought agricultural research was a man’s job!” she recalls.
But Elizabeth was on a mission. “I see African communities where poverty and hunger are seemingly huge problems with no way out,” she says. “If I put in enough effort, I can bring some solutions. My primary target group is the less privileged, and women in particular have been my friends throughout. This sometimes means subtly getting the men to consider some changes in roles.”
This sense of destiny led to Elizabeth gaining a Bachelor’s degree in Agriculture, a Diploma in Education and a Master’s in Crop Science.
A worker in a Ghanaian cooperative producing garri, or gari, a kind of granular cassava flour used to prepare a range of foods.
Turning point: cassava to help the vulnerable
During a stint of national service between academic degrees, she was based in the tiny poor village of Aworowa in the Brong Ahafo Region. There was no electricity in her room, and the street lights came on once a week.
In a poor Ghanaian community everyone has to pitch in to the heavy daily round of chores.
“We all fetched water from the stream to drink and cook,” Elizabeth recalls. The plight of the villagers inspired Elizabeth to approach a scientist engaged in root and tuber projects at the Crops Research Institute (CRI) of Ghana’s Council for Scientific and Industrial Research (CSIR). She offered to carry out some research on cassava, hoping this might help the local people.
“I saw the struggle for households,” says Elizabeth. “I lived with them for one year, which transformed my interest and focus onto the vulnerable and less privileged.”
As a result, Elizabeth established CRI cassava trials in the region, and these trials continue today with Elizabeth still in touch with the villagers.
When her year of national service finished, Elizabeth was appointed as Assistant Research Officer at CRI – their first woman to be assigned to a research project. Already, she was beginning to fulfil her destiny.
Healthy cassava plants.
Challenges and opportunities
Unlike most crops, cassava is propagated, not by seed, but using cut sections of stem like these – just one of the many challenges this previously neglected crop offers breeders.
But cassava is not the easiest crop for a young researcher to cut their teeth on. It has long been regarded as an ‘orphan’ crop – one that researchers and funders have forgotten in their drive to work with the higher profile crops of wheat, rice and maize.
Cassava is a challenging crop for breeders to work with. “In addition to factors such as pests and disease, cassava is a long-season and very labour-intensive crop. It can take a whole year before you can expect to reap any rewards, and if you don’t have a strong team who can step in at different points throughout the breeding process, you can often find unexpected results at the end of it, and then you have to start all over again,” Elizabeth says.
But while many other young researchers gave up on with cassava, Elizabeth stuck with it, knowing the importance of this crop to farmers, especially women. And this is where Elizabeth’s involvement with the CGIAR Generation Challenge Programme (GCP) really started to make a difference to her future.
During GCP’s first research phase, Elizabeth’s path crossed with GCP scientist Martin Fregene, who encouraged Elizabeth to lead the Ghana partners involved in GCP’s cassava projects. She soon climbed the GCP research ranks, receiving multiple study grants, managing projects, and mixing and mingling with elite scientists. Along the way, Elizabeth also learnt new molecular breeding techniques. More recently, she was appointed Ghana’s lead researcher for GCP’s Phase II Cassava Research Initiative.
A place at the table, and sharing joy
Elizabeth Parkes examines a healthy crop of monster roots from an improved cassava variety.
Elizabeth believes the support GCP gave her to develop her skills and capacity is what has made a difference to her own and others’ destinies as research scientists: “GCP has made us visible and attractive to others; we are now setting the pace and doing science in a more refined and effective manner. I see GCP as the pace setters.
“GCP gave you the keys to solving your own problems and put structures in place so that knowledge learnt abroad could be transferred and applied at home.
“When I first joined GCP,” Elizabeth recalls, “I saw myself as somebody from a national research programme being given a place at the table; my inputs were recognised and what I said carried weight in decision-making.”
“With the Community of Practice you can call on other scientists; you share talk, you share ideas, you share joy. We share everything together,” Elizabeth enthuses. ‘Joy’ is a word that is often on Elizabeth’s lips when she describes the help that GCP has given her and others.
“We are all forever grateful to GCP and its funders. GCP has had a huge impact on research in Ghana, especially for cassava, rice, maize and yam. All the agricultural research institutes and individual scientists who came into contact with GCP have been fundamentally transformed.”
A farmer in Benin transforms cassava into garri, or gari, used as the basis of many different dishes.
In less than a decade, Elizabeth has become a valued researcher at CRI (currently on secondment at the International Institute of Tropical Agriculture, IITA) as well as Ghana’s leading GCP-supported scientist working on cassava. But in fulfilling her own destiny, she’s also passionate about helping others to achieve their potential.
“Building human capacity is my greatest joy,” she says. Farmers, breeders and a Ghanaian private-sector company are just a few of the fortunate beneficiaries of her expertise over recent years.
“Wherever I go, whatever opportunity I have, I refer back to GCP and its capacity-building work. You see, it’s good to release new plant varieties, but it’s also good to release people who will do the job.”
Angelique Ipanga tends her cassava plants in the Democratic Republic of Congo. Cassava is often seen as a “women’s crop,” and the work of cultivating and preparing it falls largely on women’s shoulders.
Bea hadn’t planted cassava before, so she pestered Elizabeth to find out more about how to do it properly. With Elizabeth’s guidance, Bea’s cassava-growing skills flourished, and she became so successful that she was recognised as the best farmer in her community.
“These are things that make me glad… that at least I have impacted somebody who hadn’t planted cassava before, and it’s amazing,” says Elizabeth. “There are people out there who need us, and when we give them our best, they will give the world their best as well.”
Elizabeth is also passionate about helping other women researchers: “I’ve pushed to make people recognise that women can do advanced agricultural science, and do it well. To see a talented woman researcher firmly established in her career and with her kids around her is thrilling.”
And so Elizabeth is now herself firmly established in world-class agricultural research, and further interesting stories are sure to follow.
“Before GCP we really struggled, but now everybody wants to have training in Ghana. Everybody wants to have something to do with us, and I will always say thank you to GCP for that, for making us attractive as researchers,” Elizabeth says.
“I’ve stuck with cassava because that’s my destiny! I may add other root and tuber crops, but cassava is my pivot.”
Beyond the glittering coastline of what was once known as the Gold Coast, Ghana’s shrublands and rich forested hills are split by forking rivers that reach inland through the country’s lush tropics, into drier western Africa. In the past 40 years, seven major droughts have battered the people of Africa – with the most significant and devastating occurring in the Sahel region and the Horn of Africa in the early 1970s and 1980s.
This little girl in Kenya already seems to know that cassava roots are precious.
But despite the massive social disruption and human suffering that these droughts cause, life goes on. In south-eastern Ghana and in Togo, the three-million-plus people who speak the Ewe language have a word for this. It is agbeli: ‘There is life’. It is no coincidence that this word is also their name for a tropical and subtropical crop that survives through the worst times to feed Africa’s families: cassava.
Cassava is a lifeline for African people, and is a particularly important staple food for poorer farmers. More cassava is produced in Africa than any other crop, and it is grown by nearly every farming family in sub-Saharan Africa, supplying about a third of the region’s daily energy intake. In the centuries since Portuguese traders introduced this Amazonian plant to Africa, cassava has flourished, yielding up to 40 tonnes per hectare.
Hear more on just why cassava is so important to food security from Emmanuel Okogbenin, of Nigeria’s National Root Crops Research Institute, in the video below (or watch on Youtube):
African countries produced nearly 140 million tonnes of cassava in 2012 – but most of the production is subsistence farming by small-scale farmers. Even the undisputed global cassava giant, Nigeria, currently produces only just enough to feed its population – and although the country is increasingly moving towards production of cassava for export as an industrial raw material, the poorest farmers often do not produce enough to sell, or have access to these markets.
Because cassava does so well on poor soils, on marginal land and with little rainfall, it can outlast its more sophisticated crop competitors: wheat, rice and maize. In fact, under harsh conditions such as drought, the amount of energy a given area of cassava plants can produce in the form of starchy carbohydrates outstrips all other crops. Chiedozie Egesi, a plant breeder and geneticist at Nigeria’s National Root Crops Research Institute (NRCRI), describes cassava as “the crop you can bet on when every other thing is failing”.
Despite cassava’s superhero cape, however, there’s no denying that its production is not at its highest when faced with diseases, pests, low-nutrient soils and drought. How plants deal with problems like low nutrients or dry conditions is called ‘stress tolerance’ by scientists. Improving this tolerance – plus resistance to diseases and pests – is the long-term goal for staple crops around the world so that they have higher yields in the face of capricious weather and evolving threats.
In the 1980s, catastrophe struck cassava production in East and Central Africa. A serious outbreak of cassava mosaic disease (CMD) – which first slowly shrivels and yellows cassava leaves, then its roots – lasted for almost 15 years and nearly halved cassava yields in that time. Food shortages led to localised famines in 1993 and 1997.
Other diseases affecting cassava include cassava brown streak disease (CBSD), cassava bacterial blight, cassava anthracnose disease and root rot. CBSD is impossible to detect above ground. Its damage is revealed only after harvest, when it can be seen that the creeping brown lesions have spoilt the white flesh of the tubers, rendering them inedible. Many cassava diseases are transmitted through infected cuttings, affecting the next generation in the next season. Pests that also prey on cassava include the cassava green mite and the variegated grasshopper.
Between the effects of drought, diseases, pests and low soil nutrients, cassava yields vary widely – losses can total between 50 and 100 percent in the worst times.
Symptoms of cassava mosaic disease (CMD) and cassava brown streak disease (CBSD), both of which can cripple cassava yields.
GCP takes the first steps to kick start cassava research
The next step forward for cassava appeared to be research towards breeding stronger and more resilient cassava varieties. However, cassava research had long been neglected – scientists say it’s a tricky crop that has garnered far less policy, scientific and monetary interest than the comparatively glamorous crops of maize, rice and wheat.
Watch as Emmanuel tells us more about the complexities and challenges of cassava breeding in the video below (or on YouTube):
Cassava is a plant which ‘drags its feet’: creating new plants has to be done from cuttings, which are costly to cut and handle and don’t store well; the plant takes up to two years to grow to maturity; and it is onerous to harvest. Elizabeth Parkes, of Ghana’s Crops Research Institute (CRI) (currently on secondment at the International Institute of Tropical Agriculture, IITA), says the long wait can be difficult.
This is where the work of scientists funded by the CGIAR Generation Challenge Programme (GCP) came in. Plant breeder and molecular geneticist Emmanuel Okogbenin of NRCRI led the cassava research push launched in 2010. He explains that before GCP, “most national programmes didn’t really have established crop breeding programmes, and didn’t have the manpower” to do the scale of research GCP supported.
Usually, researchers looking to breed crops that are more resistant to drought, diseases and pests would use conventional breeding methods that could take considerable time to deliver any results, especially given cassava’s slow path to maturity. Researchers would be trying to select disease- and pest-resistant plants by looking at how they’re growing in the field, without any way to see the different genetic strengths each plant has.
An IITA researcher exams cassava roots in the field.
This is where new ‘molecular breeding’ tools are particularly useful, given that – genetically – cassava presents more of a challenge to breeders than its cereal counterparts. Like many other vegetatively propagated crops, cassava is highly heterozygous, meaning that the counterpart genes on paired chromosomes tend to be different versions, or alleles, rather than the same. This makes it difficult to identify good parent plants for breeding and, after these are crossed, to accurately select progeny with desired traits. Useful – or detrimental – genes can be present in a cassava plant’s genetic code but not reflected in the plant itself, making breeding more unpredictable – and adding extra obstacles to the hunt for the exact genes that code for better varieties of cassava.
Although late to the world of molecular breeding, cassava had not missed its chance. Guided by GCP’s ambitious remit to increase food security through modern crop breeding, GCP-supported scientists have applied and developed molecular breeding methods that shorten the breeding process by identifying which plants have good genes, even before starting on that long cassava growth cycle. Increasing the capacity of local plant breeders to apply these methods has great potential for delivering better varieties to farmers much faster than has traditionally been the case.
Charting cassava’s genetic material was the first step in the researchers’ molecular quest. Part of the challenge for African and South American researchers was to create a genetic map of the cassava genome. Emmanuel describes the strong foundation that these early researchers built for those coming after: “It was significant when the first draft of the cassava genome sequence was released. It enabled rapid progress in cassava research activities and outcomes, both for GCP and cassava researchers worldwide.”
Cassava on sale in Kampala, Uganda.
Once cassava’s genome had been mapped, the pace picked up. In just one year, GCP-supported scientists phenotyped and genotyped more than 1000 genetically different cassava plants – that is, measured and collected a large amount of information about both their physical and their genetic traits – searching for ‘superstar’ plants with resistance to more than one crop threat. During this process, scientists compare plant’s physical characteristics with their genetic makeup, looking for correlations that reveal regions of the DNA that seem to contain genes that confer traits they are looking for, such as resistance to a particular disease. Within these, scientists then identify sequences of DNA, or ‘molecular markers’, associated with these valuable genes or genetic regions.
Plant breeders can use this knowledge to apply an approach known as marker-assisted selection, choosing their breeding crosses based directly on which plants contain useful genes, using markers like tags. This makes producing better plant varieties dramatically faster and more efficient. “It narrowed the search at an early stage,” explains Emmanuel, “so we could select only material that displayed markers for the genetic traits we’re looking for. There is no longer any need to ship in tonnes of plant material to Africa.”
Like breadcrumbs leading to a clue, breeders use markers to lead to identifying actual genes (rather than just a site on the genome) that give certain plants desirable characteristics. However, this is a particularly difficult process in cassava. Genes are often obscured, partly due to cassava’s highly heterozygous nature. In trials in Africa, where CMD is widespread, resistant types were hard to spot when challenged with the disease, and reliably resistant parents were hard to pin down.
This meant that two decades of screening cassava varieties from South America – where CMD does not yet exist yet – had identified no CMD-resistance genes. But screening of cassava from Nigeria eventually yielded markers for a CMD-resistance gene – a great success for the international collaborative team led by Martin Fregene, who was based in Colombia at the International Center for Tropical Agriculture (CIAT).
This finding was a win for African plant breeders, as it meant they could use molecular breeding to combine the genes producing high-quality and high-yielding cassava from South America with the CMD-resistance gene found in cassava growing in Nigeria.
Chiedozie Egesi, who led the work on biotic trait markers, explains the importance of combining varieties from South America with varieties from Africa: “Because cassava is not native to Africa, those varieties are not as genetically diverse, so we needed to bring genetic diversity from the centre of origin: South America. Coupling resistance genes from African varieties with genes for very high yields from South America was critical.”
Cassava research leaps forward with new varieties to benefit farmers
GCP’s first investment phase into cassava research stimulated a sturdy injection of people, passion, knowledge and funds into the second phase of research. From the genome maps created during the first phase, some of the world’s best geneticists would now apply genomic tools and molecular breeding approaches to increase and accelerate the genetic gains during breeding, combining farmers’ favourite characteristics with strong resistances and tolerances to abiotic and biotic constraints.
These were breeder and geneticist Chiedozie Egesi (NRCRI, Nigeria), molecular geneticist Morag Ferguson (IITA), genomic scientist Pablo Rabinowicz (University of Maryland, USA) and physiologist and geneticist Alfredo Alves (Brazilian Corporation of Agricultural Research, EMBRAPA). The team shared the vision of enabling farmers to increase cassava production for cash, well beyond subsistence levels.
Garri, or gari, a kind of granular cassava flour used to prepare a range of foods.
If the Accra launch set the stage for the next five years of cassava collaboration, a breakthrough in Nigeria at the end of 2010 set the pace, with the release of Africa’s first cassava variety developed using molecular-breeding techniques. “It was both disease-resistant and highly nutritious – a world-first,” recalls Emmanuel proudly.
Known as UMUCASS33 (or CR41-10), it took its high yield and nutritional value from its South American background, and incorporated Nigerian resistance to devastating CMD attacks thanks to marker-assisted selection. It was also resistant to several other pests and diseases. UMUCASS33 was swiftly followed by a stream of similar disease-busting varieties, released and supplied to farmers.
Never before had cassava research been granted such a boost of recognition, scientific might and organisational will. And never before had there been so much farmer consultation or so many on-farm trials.
“Cassava was an orphan crop and with the help of GCP it is becoming more prominent,” says Chiedozie. “GCP highlighted and enhanced cassava’s role as a major and reliable staple that is important to millions of poor Africans.”
Another important challenge for scientists was to develop a higher-yielding cassava for water-limited environments. The aim was to keep mapping genes for resistance to other diseases and pests and then combine them with favourable genetics that increase yield in drought conditions – no easy feat. Drought’s wicked effect on cassava is to limit the bulk of the tuber, or sometimes to stop the tuber forming altogether. Emmanuel led the work on marker-assisted recurrent selection for drought.
Hear from Chiedozie on the beneficial outcomes of GCP – in terms not only of variety releases but also of attracting further projects, prestige, and enthusiastic young breeders – in the video below (or on YouTube):
Many traits and many varieties
As closely as the cassava teams in Africa were working together, Chiedozie recalls that each country’s environment demanded different cassava characteristics: “We had to select for what worked best in each country, then continue with the research from there. What works fine for East Africa may not be so successful in Nigeria or Ghana”. A core reference set representing most of the diversity of cassava in Africa was improved with the addition of over 564 varieties. Improving the reference set, says project leader Morag Ferguson, “enables the capture of many diverse features of cassava” within a relatively small collection, providing a pathway for more efficient trait and gene discovery.
While mapping of cassava’s genetic makeup carried on, with a focus on drought tolerance, researchers continued to develop a suite of new varieties. They mapped out further genes that provided CMD resistance. In Tanzania, four new varieties were released that combined resistance to both CMD and CBSD – two for the coastal belt and two for the semi-arid areas of central Tanzania. These new varieties had the potential to double the yield of existing commercial varieties. In Ghana too, disease-resistant varieties were being developed.
Built-in disease resistance can make a huge difference to the health of cassava crops. This photo shows a cassava variety resistant to African cassava mosaic virus (ACMV), which causes cassava mosaic disease (CMD), growing on the left, alongside a susceptible variety on the right.
Meanwhile in Nigeria, another variety was released in 2012 with very high starch content – an essential factor in good cassava. This is a critical element to breeding any crop, explains Chiedozie: “A variety may be scientifically perfect, based on a researcher’s perspective, but farmers will not grow it if it fails the test in terms of taste, texture, colour or starchiness.”
Geoffrey Mkamilo, cassava research leader at Tanzania’s Agricultural Research Institute, Naliendele, says that farmer awareness and adoption go hand in hand. Once they had the awareness, he says, “the farmers were knocking on our doors for improved varieties. They and NGOs were knocking and calling.”
After groundwork in Ghana and Nigeria to find potential sources of resistance, cassava varieties that are resistant to bacterial blight and green mites were also developed in Tanzania and then tested. By the time GCP closed in December 2014, these varieties were on their way to commercial breeders for farmers to take up.
Scientists seeking to resolve the bigger challenge of drought resistance have achieved significant answers as well. Researchers have been able to map genetic regions that largely account for how well the crops deal with drought.
Hunt for ‘super powered’ cassava
The hunt was on for drought-tolerance genes in African cassava plants. The end goal was to find as many different drought-related genes as possible, then to put them all together with the applicable disease and pest resistance genes, to make a ‘super powered’ set of cassava lines. Molecular breeders call this process ‘pyramiding’, and in Ghana, Elizabeth Parkes led these projects.
With the help of Cornell University scientists, the researchers compared plants according to their starch content, how they endured a dry season, how they used sunlight and how they dealt with pests and diseases.
Fourteen gene regions or quantitative trait loci (QTLs) were identified for 10 favourable traits from the genetic material in Ghana, while nine were found for the plants in Nigeria – with two shared between the plants from both Ghana and Nigeria. After that success, the identified genes were used in breeding programmes to develop a new generation of cassava with improved productivity.
Pyramiding is important in effective disease resistance; Chiedozie explains in the video below (or on YouTube):
New cassava varieties rich in pro-vitamin A have a telltale golden hue.
The research has also delivered results in terms of Vitamin A levels in cassava. In 2011, the NRCRI team, together with IITA and HarvestPlus (another CGIAR Challenge Programme focussed on the nutritional enrichment of crops), released three cassava varieties rich in pro-vitamin A, which hold the potential to provide children under five and women of reproductive age with up to 25 percent of their daily vitamin A requirement. Since then, the team has aimed to increase this figure to 50 percent. In 2014, they released three more pro-vitamin A varieties with even higher concentrations of beta-carotene.
A field worker at IITA proudly displays a high-yielding, pro-vitamin A-rich cassava variety (right), compared with a traditional variety (left).
The new varieties developed with GCP support are worth their weight in gold, says Chiedozie: “Through these varieties, people’s livelihoods can be improved. The food people grow should be nutritious, resistant and high-yielding enough to allow them to sell some of it and make money for other things in life, such as building a house, getting a motorbike or sending their kids to school.”
Turning from Nigeria to Tanzania, Geoffrey has some remarkable numbers. He says that the national average cassava yield is 10.5 tonnes per hectare. He adds that a new cassava variety, PWANI, developed with GCP support and released in 2012, has the potential to increase yields to 51 tonnes per hectare. And they don’t stop there: the Tanzanian researchers want to produce three million cuttings and directly reach over 2,000 farmers with these new varieties, then scale up further.
A farmer tends her cassava field in northern Tanzania.
Cassava grows up: looking ahead to supporting African families
Emmanuel reflects on how the first release of a new disease-resistant high-yielding cassava variety took fundamental science towards tangible realities for the world’s farmers: “It was a great example of a practical application of marker technology for selecting important new traits, and it bodes well for the future as markers get fully integrated into cassava breeding.”
Emmanuel further believes that GCP’s Cassava Research Initiative has given research communities “a framework for international support from other investors to do research and development in modern breeding using genomic resources.” Evaluations have demonstrated that molecular-assisted breeding can slash between three and five years from the timeline of developing better crops.
Women tend to bear most of the burden of cassava cultivation and preparation. Here a Congolese woman pounds cassava leaves – eaten in many regions in addition to cassava roots – prior to cooking a meal for her family.
But, like cassava’s long growth cycle underground, Emmanuel knows there is still a long road to maturity for cassava as a crop for Africa and in research. “Breeding is just playing with genetics, but when you’re done with that, there is still a lot to do in economics and agronomics,” he says. Revolutionising cassava is about releasing improved varieties carefully buttressed by financial incentives and marketing opportunities.
Rural women in particular stand to benefit from improved varieties – they carry most of the responsibility for producing, processing and marketing cassava. So far, Elizabeth explains: “Most women reported an increase in their household income as a result of the improved cassava, but that is still dependent on extra time spent on cassava-related tasks” – a burden which she aims to diminish.
Elizabeth emphasises that future improvement research has to take a bottom-up approach, first talking to female farmers to ensure that improved crops retain characteristics they already value in addition to the new traits. “Rural families are held together by women, so if you are able to change their lot, you can make a real mark,” she says. Morag echoes this hope: “We are just starting to implement this now in Uganda; it’s a more farmer-centric approach to breeding”. The cassava teams emphasise the importance of supporting women in science too; the Tanzanians teams are aiming for a target of 40 percent women in their training courses.
Meet Elizabeth in the podcast below (or on PodOmatic), and be inspired by her passion when it comed to women in agriculture and in science:
This direct impact goes much further than individuals, says Chiedozie. “GCP’s daring has enabled many national programmes to be self-empowered, where new avenues are unfolding for enhanced collaboration at the local, national and regional level. We’re seeing a paradigm shift.” And Chiedozie’s objectives reach in a circle back to his compatriots: “Through GCP, I’ve been able to achieve my aims of using the tools of science and technology to make the lives of poor Africans better by providing them with improved crops.”
GCP has been crucial for developing the capacity of countries to keep doing this level of research, says Chiedozie: “The developing-country programmes were never taken seriously,” he says. “But when the GCP opportunity to change this came up we seized it, and now the developing-country programmes have the boldness, capacity and visibility to do this for themselves.”
Emmanuel says his proudest moment was when GCP was looking for Africans to take up leadership roles. “They felt we could change things around and set a precedent to bring people back to the continent,” he says. “They appreciated our values and the need to install African leaders on the ground in Africa rather than in Europe, Asia or the Americas.”
“If you want to work for the people, you have to walk with the people – that’s an African concept. Then when you work with the people, you really understand what they want. When you speak, they know they can trust you.” GCP trusted and trod where others had not before, Chiedozie says.
Elizabeth agrees: “In the past, the assumption was always that ‘Africa can’t do this.’ Now, people see that when given a chance to get around circumstances – as GCP has done for us through the provision of resources, motivation, encouragement and training – Africa can achieve so much!”