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research: Maize breeding

A farmer in Tanzania holds a handful of drought-tolerant maize seed. (Photo: Anne Wangalachi/CIMMYT)

Molecular breeding speeds development of better seeds

Written by Emma Orchardson on . Posted in Features.

To adequately confront rapidly changing plant pests and diseases and safeguard food security for a growing population, breeders — in collaboration with their partners — have to keep testing and applying new breeding methods to deliver resilient seed varieties at a much faster rate using minimal resources. Molecular markers are essential in this regard and are helping to accelerate genetic gains and deliver better seed to smallholders across sub-Saharan Africa in a much shorter timeframe.

Progress made so far in molecular plant breeding, genetics, genomic selection and genome editing has contributed to a deeper understanding on the role of molecular markers and greatly complemented breeding strategies. However, phenotyping remains the single most costly process in plant breeding, thus limiting options to increase the size of breeding programs.

Application of molecular markers increases the ability to predict and select the best performing lines and hybrids, prior to selection in the field. “This enables breeders to expand the size of a breeding program or the populations they work on using the same amount of resources,” says Manje Gowda, a maize molecular breeder at the International Maize and Wheat Improvement Center (CIMMYT).

“There are three stages in the use of molecular markers: discovery, validation and deployment,” he explains. “At the discovery phase, the objective is to find molecular markers associated or tightly linked with the trait of interest, while also assessing whether the trait is more complex or easier to handle with few markers for selection.”

The molecular markers identified at the discovery stage are validated in independent bi-parental or backcross populations, and the marker trait associations — which are consistent across different genetic backgrounds and diverse environments — are then moved to the deployment stage. Here, they are considered for use in breeding either as part of marker assisted selection or forward breeding, marker assisted back crossing and marker assisted recurrent selection.

Screening for resistance markers

CIMMYT scientists have discovered several marker trait associations for crop diseases including maize lethal necrosis (MLN), maize streak virus (MSV), corn rust and turcicum leaf blight. All these trait-associated markers have been validated in biparental populations.

For MLN, after screening several thousands of lines, researchers identified a few with resistance against the viral disease, namely KS23-5 and KS23-6. These lines were obtained from synthetic populations developed by Kasetsart University in Thailand and serve as trait donors. Researchers were able to use these as part of forward breeding, producing doubled haploid (DH) lines by using KS23-6 as one parent and screening for the presence of MLN resistance genes.

“This screening helps eliminate the lines that may carry susceptible genes, without having to phenotype them under artificial inoculation,” says Gowda. “These markers are also available to all partners to screen for MLN resistance, thereby saving on costs related to phenotyping.”

Scientists also used these MLN resistance markers to introgress the MLN resistance into several elite lines that are highly susceptible to the disease but have other desirable traits such as high grain yield and drought tolerance. The marker-assisted backcrossing technique was used to obtain MLN resistance from the KS23-5 and KS23-6 donor lines. This process involves crossing an elite, commercial line — as a recurrent parent in the case of CIMMYT elite lines — with a donor parent line (KS23) with MLN resistance. These were then backcrossed over two to three cycles to improve the elite line carrying MLN resistance genes. In the past three years, more than 50 lines have been introgressed with the MLN resistance gene from KS23-6 donor line.

Aida Zewdu Kebede, a PhD student at the University of Hohenheim, sits next to an experimental plot for doubled haploid maize in Agua Fría, Mexico. (Photo: Thomas Lumpkin/CIMMYT)
Aida Zewdu Kebede, a PhD student at the University of Hohenheim, sits next to an experimental plot for doubled haploid maize in Agua Fría, Mexico. (Photo: Thomas Lumpkin/CIMMYT)

An impetus to breeding programs

“The work Manje Gowda has been carrying out is particularly important in that it has successfully moved from discovery of valuable markers and proof-of-concept experiments to scalable breeding methods which are being used effectively,” says CIMMYT Trait Pipeline and Upstream Research Coordinator Mike Olsen. “Enabling routine implementation of molecular markers to increase selection efficiency of breeding programs in the context of African maize improvement is quite impactful.”

At CIMMYT, Gowda’s team applied genomic selection at the early stage of testing the breeding pipeline for different product profiles. “The objective was to testcross and phenotype 50% of the Stage One hybrids and predict the performance of remaining 50% of the hybrids using molecular markers,” Gowda explains.

The team have applied this strategy successfully each year since 2017, and the results of this experiment show that selection efficiency is the same as when using phenotypic selection, but using only 32% of the resources. From 2021 onwards, the aim is to use the previous year’s Stage One phenotypic and genotypic data to predict 100% of the lines. This will not only save the time but improve efficiency and resource use. The previous three-year Stage One historical data is helping to reduce the phenotyping of lines from 50% to 15%, with an increase in saving resources of up to 50%.

For the commercial seed sector, integrating molecular marker-based quality control measures can help deploy high-quality seeds, an important factor for increasing crop yields. In sub-Saharan Africa, awareness on marker-based quality has improved due to increased scientist and breeder trainings at national agricultural research systems (NARS), seed companies and national plant protection organizations, as well as regulators and policymakers.

Currently, many NARS and private sector partners are making it mandatory to apply marker-based quality control to maintain high-quality seeds. Since NARS and small- and medium-sized seed companies’ breeding programs are smaller, CIMMYT is coordinating the collection of samples from different partners for submission to service providers for quality control purposes. CIMMYT staff are also helping to analyze quality control data and interpret results to sharing with partners for decision-making. For the sustainability of this process, CIMMYT is training NARS partners on quality control, from sample collection to data analyses and interpretation, and this will support them to work independently and produce high-quality seed.

Such breeding improvements have become indispensable in supporting maize breeding programs in the public and private sectors to develop and deliver improved maize varieties to smallholder farmers across sub-Saharan Africa.

A farmer in Tanzania stands in front of her maize plot where she grows improved, drought tolerant maize variety TAN 250. (Photo: Anne Wangalachi/CIMMYT)
A farmer in Tanzania stands in front of her maize plot where she grows improved, drought tolerant maize variety TAN 250. (Photo: Anne Wangalachi/CIMMYT)
Maize and wheat fields at the El Batán experimental station. (Photo: CIMMYT/Alfonso Cortés)

Scientific opportunities and challenges

Written by Emma Orchardson on . Posted in Blogs.

Maize and wheat fields at the El Batán experimental station. (Photo: CIMMYT/Alfonso Cortés)
Maize and wheat fields at the El Batán experimental station. (Photo: CIMMYT/Alfonso Cortés)

The first meetings of the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) wheat and maize science and technical steering committees — WSC and MSC, respectively — took place virtually on 25th and 28th September.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) sit on both committees. In the WSC they are joined by wheat experts from national agricultural research systems (NARS) in Bangladesh, Ethiopia, Kenya, India, and Nepal; and from Angus Wheat Consultants, the Foreign, Commonwealth & Development Office (FCDO), HarvestPlus, Kansas State University and the Roslin Institute.

Similarly, the MSC includes maize experts from NARS in Ethiopia, Ghana, Kenya and Zambia; and from Corteva, the Foundation for Food and Agriculture Research (FFAR), the International Institute for Tropical Agriculture (IITA), SeedCo, Syngenta, the University of Queensland, and the US Agency for International Development (USAID).

During the meetings, attendees discussed scientific challenges and opportunities for AGG, and developed specific recommendations pertaining to key topics including breeding and testing scheme optimization, effective engagement with partners and capacity development in the time of COVID-19, and seed systems and gender intentionality.

Discussion groups noted, for example, the need to address family structure in yield trials, to strengthen collaboration with national partners, and to develop effective regional on-farm testing strategies. Interestingly, most of the recommendations are applicable and valuable for both crop teams, and this is a clear example of the synergies we expect from combining maize and wheat within the AGG project.

All the recommendations will be further analyzed by the AGG teams during coming months, and project activities will be adjusted or implemented as appropriate. A brief report will be submitted to the respective STSCs prior to the second meetings of these committees, likely in late March 2021.

Usman Kadir and his family de-husk maize on their farm in Ethiopia. (Photo: Apollo Habtamu/ILRI)

Faster results at a lower cost

Written by Emma Orchardson on . Posted in Blogs.

Usman Kadir and his family de-husk maize on their farm in Ethiopia. (Photo: Apollo Habtamu/ILRI)
Usman Kadir and his family de-husk maize on their farm in Ethiopia. (Photo: Apollo Habtamu/ILRI)

The current COVID-19 pandemic — and associated measures to reduce its spread — is projected to increase extreme poverty by 20%, with the largest increase in sub-Saharan Africa, where 80 million more people would join the ranks of the extreme poor. Accelerating the process of delivering high-quality, climate resilient and nutritionally enriched maize seed is now more critical than ever.However, developing these varieties is not a rapid or cheap process. Over the course of five years, researchers on the Stress Tolerant Maize for Africa (STMA) project developed a range of tools and technologies to reduce the overall cost of producing a new high yielding, stress tolerant hybrids for smallholder farmers in the region.

Maize breeding starts with crossing two parents and essentially ends after testing their great-great-great-great grandchildren in as many locations as possible. This allows plant breeders to identify the new varieties which will perform well in the conditions faced by their target beneficiaries — in the case of STMA, smallholder farmers in Africa. In other parts of the world, new tools and technologies are routinely added to breeding programs to help reduce the cost and time it takes to produce new varieties.

Scientists on the STMA project focused on testing and scaling new tools specifically for maize breeding programs in sub-Saharan Africa and began by taking a closer look at the most expensive part of the breeding process: phenotyping or collecting precise information on plant traits.

“Within a breeding program, phenotyping is the single most costly step,” explains CIMMYT molecular breeder Manje Gowda. “Molecular technologies provide opportunities to reduce this cost.” The research team tested two methods to speed up this step and make it more cost efficient: forward breeding and genomic selection.

Speeding up a long and costly process

Two important traits maize breeders look for in their plant progeny are susceptibility for two key maize diseases: maize streak virus (MSV) and maize lethal necrosis (MLN). In traditional breeding, breeders must extensively test lines in the field for their susceptibility to these diseases, and then remove them before the next round of crossing. This carries a significant cost.

Using a process called forward breeding, scientists can screen for DNA markers known to be associated with susceptibility to these diseases. This allows breeders to identify lines vulnerable to these diseases and remove them before field testing.

Scientists on the STMA project applied this approach in CIMMYT breeding programs in eastern and southern Africa over the past four years, saving an estimated $300,000 in field costs. Under the AGG project, research will now focus on applying forward breeding to identify susceptibility for another fast-spreading maize pest, fall armyworm, as well as extending use of this method in partners’ breeding programs.

A CIMMYT research associate inspects maize damaged by fall army worm at KALRO Kiboko Research Station in Kenya. (Photo: Peter Lowe/CIMMYT)
A CIMMYT research associate inspects maize damaged by fall army worm at KALRO Kiboko Research Station in Kenya. (Photo: Peter Lowe/CIMMYT)

Forward breeding is ideal for “simple” traits which are controlled by a few genes. However, other desired traits, such as tolerance to drought and low nitrogen stress, are genetically complex. Many genes control these traits, with each gene only contributing a little towards overall stress tolerance.

In this case, a technology called genomic selection can be of service. Genomic selection estimates the performance, or breeding value, of a line based largely on genetic information. Genomic selection uses more than 5,000 DNA markers, without the need for precise information about what traits these markers control. The method is ideal for complicated traits such as drought and low nitrogen stress tolerance, where hundreds of small effect genes together largely control how a plant grows under these stresses.

CIMMYT scientists used this technology to select and advance lines for drought tolerance. They then tested these lines and compared their performance in the field to lines selected conventionally. They found that the two sets of resulting hybrid varieties — those advanced using genomic selection and those advanced in the field — showed the same grain yield under drought stress. However, genomic selection only required phenotyping half the lines, achieving the same outcome with half the budget.

Innovations in the field

While DNA technology is reducing the need for extensive field phenotyping, research is also underway to reduce the cost of the remaining necessary phenotyping in the field.

Typically, many traits — such as plant height or leaf drying under drought stress — are measured by hand, using the labor of large teams of people. For example, plant and ear height is traditionally measured by a team of two using a meter stick.

Mainasarra Zaman-Allah, a CIMMYT abiotic stress phenotyping specialist based in Zimbabwe, has been developing faster, more accurate ways to measure these traits.  He implemented the use of a small laser sensor to measure plant and ear height which only requires one person. This simple yet cost effective tool has reduced the cost of measuring these traits by almost 60%. Similarly, using a UAV-based platform has reduced the cost of measuring a trait known as canopy senescence — leaf drying associated with drought susceptibility —by over 65%.

The identification of plants which are tolerant to key diseases has traditionally involved scoring the severity of disease in each plot visually, but walking through hundreds of plots daily can lead to errors in human judgement. To combat this, CIMMYT biotic stress phenotyping specialist LM Suresh collaborated with Jose Luis Araus and Shawn Kefauver, scientists at the University of Barcelona, Spain, to develop image analysis software that can quantify disease severity, thereby avoiding problems associated with unintentional human bias.

Plant breeders need uniform, or homozygous, lines for selection. With conventional plant breeding this is difficult: no matter how many times you cross a line, a small amount of DNA will remain heterozygous — having two different alleles of a particular gene — and reduce accuracy in line selection.

A technology called doubled haploid allows breeders to develop homozygous lines within two seasons. While this technology has been used in temperate maize breeding programs since the 1990s, it was not available for tropical environments until 10 years ago. In 2013, thanks to joint work with Kenyan partners at the CIMMYT Doubled Haploid facility in Kiboko, this technology was made available to African breeding programs. Now Vijay Chaikam, a CIMMYT doubled haploid specialist based in Kenya, is working towards reducing the cost of this technology as well.

The efforts begun by the STMA research team is now continuing under the Accelerating Genetic Gains in Maize and Wheat for Improved Livelihoods (AGG) project. As this work is carried forward, the next crucial step is ensuring that the next generation of African maize breeders have access to these technologies and tools.

“Improving national breeding programs will really drive success in raising maize yields in the stress prone environments faced by many farmers in our target countries,” says Mike Olsen, CIMMYT’s upstream trait pipeline coordinator. Under AGG, in collaboration with the CGIAR Excellence in Breeding Program, these tools will be scaled out.

Patience Ndaruza

Written by Emma Orchardson on . Posted in Uncategorized.

Patience Ndaruza is a field assistant with CIMMYT’s Global Maize Program, based in Zimbabwe.

Unique partnership to transform maize breeding and production in Africa

Written by Marta Millere on . Posted in Features.

Scientists part of the Seed Production Technology for Africa (SPTA) and the Maize Lethal Necrosis Gene Editing projects are leveraging innovative technologies to transform seed production systems and speed up the delivery of disease resistance in elite new hybrids. This research is helping smallholder farmers in sub-Saharan Africa to access high-quality seed of new hybrids that were bred to perform under stressful low-input, drought-prone conditions, including farming regions impacted by maize lethal necrosis (MLN).

Fast delivery of MLN-tolerant varieties

The fight against maize lethal necrosis (MLN) has persisted for almost ten years now.

Collaborative efforts in diagnostics, management and systematic surveillance have limited its spread and confined the disease to the eastern Africa region. However, ongoing work is required to efficiently develop MLN-tolerant varieties for smallholders in endemic areas and prepare for the potential further movement of the disease.

“Maize lethal necrosis still exists. It has not been eradicated. Even though it has reduced in its prevalence and impact, it is still present and is a latent threat in Ethiopia, Kenya, Rwanda, Tanzania and Uganda, with potential to spread further,” said B.M. Prasanna, director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize.

“That is why the work of the gene editing project is critical to rapidly change the genetic component of those susceptible parent lines of popular hybrids into MLN-tolerant versions,” said Prasanna. Scientists will edit the four parent lines of two popular hybrids, currently grown by farmers in Kenya and Uganda, which are susceptible to MLN. The edited MLN-tolerant lines will be used to make MLN-tolerant versions of these drought-tolerant hybrids.

Through gene editing technology, the time it takes to develop hybrids using traditional breeding methods will be cut in half. By 2025, the edited MLN-tolerant hybrids will be available for planting on approximately 40,000 hectares by about 20,000 Kenyan farmers.

A non-pollen-producing maize plant (on the left) on farm trial in Zimbabwe. (Photo: Jill Cairns/CIMMYT)
A non-pollen-producing maize plant (on the left) on farm trial in Zimbabwe. (Photo: Jill Cairns/CIMMYT)

Business as unusual

The unique seed production technology developed by Corteva Agriscience seeks to transform the seed production process in sub-Saharan Africa. This technology utilizes a dominant non-pollen producing maize gene to create female plants that are unable to produce pollen.

Seed companies that use seed production technology eliminate the need to detassel the female parent: a manual process through which tassels are removed from plants to prevent self-pollination and ensure that the intended male parent is the only source of pollen in the hybrid seed production field. Targeted small and medium-size seed companies could make significant savings to the cost of production if they were to eliminate manual detasseling. The method also helps to ensure the purity of the hybrid seed by removing the risk of unintentional self-pollination.

Hybrids produced using the seed production technology, characterized as 50 percent non-pollen producing (FNP), are unique since only half of the plants will produce pollen in the field. FNP hybrids re-allocate energy from the tassel and pollen production to grain formation, thus delivering an additional 200 kilograms per hectare yield advantage to the farmer. This represents a 10 percent productivity boost for farmers who will harvest approximately 2 tons per hectare, the average maize yield across sub-Saharan Africa. Farmers engaged in participatory research have demonstrated preference for FNP hybrids and associate the trait with higher yield and larger ear size.

As the first phase of Seed Production Technology for Africa (SPTA) wraps up, the collaborators are preparing for the next phase that will focus on commercializing, scaling up and increasing smallholders’ access to FNP. “This is among the unique partnerships funded by the foundation and I am hopeful that this incredible work will continue through the next phase,” said Gary Atlin, program officer at the Bill & Melinda Gates Foundation.

Resistant hybrid (on the right) grows beside a susceptible commercial check at the Kenya Plant Health Inspectorate Services' (KEPHIS) National Performance Trial. (Photo: CIMMYT)
Resistant hybrid (on the right) grows beside a susceptible commercial check at the Kenya Plant Health Inspectorate Services’ (KEPHIS) National Performance Trial. (Photo: CIMMYT)

A win-win collaboration

Research and development work under the SPTA and the MLN Gene Editing projects has immensely benefited from the support of public and private partners. Seed companies and national institutions have contributed to improving access to and knowledge of these technologies as well as creating a crucial link with farmers. Ongoing engagement with regulatory agencies through the different stages of the projects ensures transparency and fosters understanding.

In order to assess the progress of these two initiatives, representatives from regulatory agencies, seed trade associations, seed companies, national agricultural institutions and funders came together for a virtual meeting that was hosted on July 29, 2020.

“KALRO embraces partnerships such as those that are delivering these two projects. That synergy helps us to resolve challenges faced by farmers and other actors in various agricultural value chains,” observed Felister Makini, deputy director general of Crops at KALRO.

As the primary technology provider, Corteva Agriscience provides the seed production technology system on a royalty-free basis and grants access to key gene editing technologies, which are the foundation for the two projects. Corteva Agriscience is also actively involved in project execution through collaborative scientific support.

“We have appreciated the opportunity to work with CIMMYT, KARLO, Agricultural Research Council (ARC) of South Africa and the Bill & Melinda Gates Foundation to bring some of the technologies and tools from Corteva to address significant challenges facing smallholder farmers in Africa. We could not have done this alone, it requires the partnerships that exist here to bring forth these solutions,” said Kevin Diehl, director of the Global Seed Regulatory Platform at Corteva Agriscience.

Breaking Ground: Yoseph Beyene breeds desirable maize varieties for smallholder farmers in sub-Saharan Africa

Written by Rodrigo Ordóñez on . Posted in Features.

About 25 years ago, Yoseph Beyene first heard about the International Maize and Wheat Improvement Center (CIMMYT) from one of his professors, back when he was pursuing his undergraduate degree in Plant Science at Haramaya University in Ethiopia. “The professor, whom I regard as a great mentor, (…) always told me that if I ever got an opportunity to work at CIMMYT, I should not hesitate to take it up, as it was a great place to conduct maize breeding,” recollects Beyene, now a maize breeder at CIMMYT. He grew up in Alem Ketema, a village located 190 km north of Addis Ababa, Ethiopia’s capital.

In retrospect, he did not know this would change his perspective on how he viewed crops, especially maize, on smallholder farms. Like many other families in Alem Ketema, his family attended to their small farm to meet their food and nutritional needs. Most people practiced subsistence farming, intertwined with livestock keeping, on small plots that were typically less than 2 hectares. At the backyard of his family’s farm, different crops such as maize, sorghum and teff were grown. As a child, he never quite registered in his mind that farmers grew mainly recycled seed. “In hindsight, I can say that the yield of a crop such as maize was just about 1.5 tons per hectare at the time,” he reckons.

Such low yield potential meant feeding relatively large family sizes of about seven people was a tall order. It did not help that crops such as maize and wheat were frequently affected by diseases and pests and erratic rains, which diminished yields. It was not until his high school days when he had firsthand experience with high-yielding improved crop varieties. As part of the farm management class, he actively participated in the school’s farm management unit. He got to appreciate the yield variation between improved and local varieties, grown on the school plots. These improved seed, he quickly realized, were the ideal antidote to the low yield farmers obtained. 

Struck by an epiphany

“This was like a eureka moment for me. When I realized that it was possible to improve and deliver desirable seed varieties that could double farmers’ yields, I decided to study plant breeding at the university. If only the farmers back in my village knew about the improved seed and adopted them at the time, it could not only have helped solve the problems of food insecurity but also bettered their livelihoods,” he ponders.

When he enrolled for a PhD in Plant Breeding and Genetics at the University of Pretoria, he did his research in highland maize in collaboration with CIMMYT in Ethiopia. Upon completion, he was appointed as a senior cotton breeder at South Africa’s Agricultural Research Council (ARC), where he worked for one and a half years.

“One day, I saw an advertisement in which CIMMYT was looking for a maize breeder. I applied, went for the interview and was happy to get the position. That was in 2008,” he says.

The right tool for the right variety

Biotic and abiotic stresses are becoming more frequent and vicious because of climate change and there is growing urgency to tackle them to avert future potential food crises.

Beyene’s current research focuses on developing high-yielding and climate-resilient maize inbred lines and hybrids for sub-Saharan Africa. He uses  conventional and molecular breeding, including integration of novel tools and techniques, such as doubled haploid, and marker-assisted recurrent section and genomic selection. Over the years, he has developed at least 25 new drought-tolerant maize hybrids recommended for commercialization in Kenya, Mozambique, Uganda, South Africa and Tanzania. Currently, 23 seed companies have been engaged to produce and market the released hybrids through sub-licensing.

Presently, as the Regional Breeding Coordinator for Africa, he is responsible for assessing the progress of implementing product profile-based breeding, appropriate germplasm exchange within and across regional breeding hubs, and ascertaining the progress on new initiatives by regional breeding teams.

A long-term endeavor

Breeding is a costly, time consuming and complex exercise. “It takes at least 10 years from crossing to release using pedigree breeding because the hybrids should be evaluated in multiple years and tested in multiple locations, which increases costs and time of the breeding cycle. You have to appreciate the fact that you are not breeding for now but for the future,” he says.

“As a breeder, you have to keep testing new tools and techniques to make breeding more efficient. Yet, resources are not always constant but inadequate. Stresses are becoming more urgent and vicious, despite increased urgency in tackling them to avert a potential food crises,” he says.

To reduce the time and accelerate genetic gains, Beyene and his colleagues at CIMMYT are currently applying the genomic selection technique for maize breeding, using it to predict the performance of un-phenotyped genotypes at early stage of testing. He and his colleagues recently published their research comparing genomic selection with phenotypic selection, as used by CIMMYT’s maize breeding program in sub-Saharan Africa. They found that the use of genomic selection for yield under optimum and drought conditions in tropical maize can produce selection candidates with similar performance as those generated from conventional phenotypic selection, but at a lower cost. They concluded that this strategy should be effectively incorporated into maize breeding pipelines to enhance breeding program efficiency.

Breeding challenges notwithstanding, Beyene feels fulfilled whenever he sees a farmer has planted a variety that he helped breed. “The epitome of my inspiration is when there is a smile on their face because of the variety’s good performance on their farm,” he says.

Interacting with the farmers and seed companies provides an opportunity for him to learn, understand their varietal preferences as well as appreciate the impact that his work has on their operations. He is also actively engaged in building the capcity of public and private partners, and supervising master’s and doctoral students from various countries. He has published more than 50 articles in journals.

The life of a breeder is not as lonely and boring as some would think. Beyene creates time to be with his three children, playing with them and helping with their homework, taking them out for social events. He also dedicates time to watch football, reality television, comedy and drama with his family.

Thokozile Ndhlela

Written by Emma Orchardson on . Posted in Uncategorized.

Thokozile Ndhlela is a maize line development breeder with CIMMYT’s Global Maize Program, based in Zimbabwe. Her work mainly involves breeding for stress tolerant and nutritious maize varieties to boost food and nutrition security, especially in developing countries.

A seed company representative explains to farmers the merits of the variety on this plot. (Photo: Joshua Masinde/CIMMYT)

Seeing is believing

Written by Rodrigo Ordóñez on . Posted in Features.

Nancy Wawira strolls through a small plot of maize at Kithimu, in Kenya’s Embu County. She is charmed by the attributes of a maize variety that can yield 2,700kg per acre or more. The variety can endure drought-like conditions, matures in less than 120 days and has potential for double-cobbing.

Wawira is visiting a demonstration farm to witness the performance of several high yielding, early to medium maturing, drought-tolerant maize varieties.

By coming to this demonstration farm, Wawira hoped to identify a newer maize variety she could plant on her quarter-acre of land to get higher yield. The plot she stood on was the exact replica of what she was looking for. “Occasions such as this field day are very important for me and I always endeavor to attend them, as there is always something new to see or learn,” she says.

On her farm, she has been planting one of the old but popular commercial varieties suitable for this mid-altitude ecology. She normally harvests 4 bags of maize, of 90kg each, every season. However, if there is not enough rain or if there are pests or diseases, which is often the case, she harvests just 2 bags or less. This is hardly enough to meet her family’s food requirements for the year.

Switching to the maize variety she was interested in, and applying recommended farming practices, she could harvest 6 bags per season or more.

“Today, I have learnt how to improve my farming,” says Wawira. “Even when I access the variety that is high yielding, drought-tolerant and can mature in about three and a half months, as I witnessed on one of the plots, I still need to pay attention to proper crop husbandry related to spacing, timing of the planting, seed, fertilizer and pesticide application besides weed control,” she says.

Nancy Wawira examines maize in one of the demo plots. (Photo: Joshua Masinde/CIMMYT)
Nancy Wawira examines maize in one of the demo plots. (Photo: Joshua Masinde/CIMMYT)

Made-to-order

Wawira was one of the more than 400 farmers from nearby Manyatta sub-county visiting the demonstration farm on February 7, 2020. They were able to see varieties and learn about their traits, invited by the Seed Trade Association of Kenya (STAK) with the support of the International Maize and Wheat Improvement Center (CIMMYT).

The demonstration is a continuation of the work started under the Drought Tolerant Maize for Africa Seed Scaling (DTMASS) project and later under the Stress Tolerant Maize for Africa (STMA) project.

Officials from Embu County, led by its minister in charge of agriculture Jamleck Muturi, were present during the farmers’ visit. Ten seed firms, some of which use CIMMYT’s germplasm for seed propagation and marketing, participated as well.

“Several of our member seed companies are showcasing the varieties developed through CIMMYT’s breeding pipeline,” said Duncan Ochieng’, the chief executive officer of STAK. “The maize varieties showcased on these demo farms were designed to be drought-tolerant, high yielding and range from early to medium maturing. These varieties are juxta-posted with other commercial varieties suitable for this region.”

During visits to demonstration farms, farmers give feedback on their variety preferences. Seed companies can then align their breeding, germplasm-access requests, seed production or marketing plans with farmers’ expectations.

Some of the farmers who participated in the field day in Embu County, Kenya. (Photo: Joshua Masinde/CIMMYT)
Some of the farmers who participated in the field day in Embu County, Kenya. (Photo: Joshua Masinde/CIMMYT)
Jackline Wanja in one of the demo plots of the variety she liked. (Photo: Joshua Masinde/CIMMYT)
Jackline Wanja in one of the demo plots of the variety she liked. (Photo: Joshua Masinde/CIMMYT)
A seed company representative shows seeds to a farmer during the visit to the demonstration farm. (Photo: Joshua Masinde/CIMMYT)
A seed company representative shows seeds to a farmer during the visit to the demonstration farm. (Photo: Joshua Masinde/CIMMYT)
STAK chief executive officer Duncan Ochieng' examines a maize cob in one of the demo plots. (Photo: Joshua Masinde/CIMMYT)
STAK chief executive officer Duncan Ochieng’ examines a maize cob in one of the demo plots. (Photo: Joshua Masinde/CIMMYT)

Dire traits

Farming stresses such as pests, diseases, heat and drought have made targeted breeding a critical necessity.

Young farmers are increasingly choosing varieties that can mature faster, typically in less than three months. They also favor varieties that offer higher yield than the popular commercial varieties, many of which have been on the market for at least a decade. Other sought-after traits are good performance in low or erratic rains, tolerance to maize lethal necrosis, reduced lodging, and efficiency in nitrogen use.

Jackline Wanja, 25, relies on her one-acre farm for survival. “On average, I harvest about 25 bags per acre. On the demo farm, I got to know of a variety than can yield at least 30 bags per acre. I also learnt that the variety is not only drought-resilient but can also mature in about three and a half months. This is the variety that I plan to plant my farm next season,” Wanja said.

For John Njiru, 52, a higher-yielding variety with a lot of foliage, which remains green even after the maize cob has dried, is what he came looking for. For this farmer with 12 acres of land, the green maize foliage is a significant source of income when sold to livestock keepers. Njiru feeds his own livestock with it, making substantial savings on animal feed expenditure. “If this variety is as high yielding as I have been made to understand and can offer me at least 30 bags per acre, I would be a happy farmer. My farming would be very profitable,” he says.

John Njiru on a demo plot of the variety he liked. (Photo: Joshua Masinde/CIMMYT)
John Njiru on a demo plot of the variety he liked. (Photo: Joshua Masinde/CIMMYT)

Breaking Ground: Aparna Das leads efficient and demand-driven maize research

Written by Jérôme Bossuet on . Posted in Features.

Getting a good maize harvest, or just enough to feed the family, has always been a challenge for maize small farmers in developing countries. Faced with variable rainfall, heat waves, insect attacks or diseases, they rarely yield more than two tons of maize per hectare, and sometimes lose their crops altogether. Climate change, invasive pests like fall armyworm or new diseases like maize lethal necrosis could jeopardize even further the livelihoods of maize farmers and trigger severe food crises.

In this scenario, the lives and income of maize farmers rely on good seeds: seeds that are climate-resilient, pest- and disease-resistant, and that grow and yield well under local conditions, often with minimum inputs.

“That is where the maize improvement research at the International Maize and Wheat Improvement Center (CIMMYT) plays a crucial role in this challenge of food security. You need to develop the right location-specific varieties that farmers want, that partner seed companies are willing to produce, in a cost- and time-efficient way,” says Aparna Das. She joined CIMMYT’s Global Maize research program in August 2018 as Technical Program Manager.

“My role is to work  with and guide the Breeding and Seed Systems team, so that our research is more client- and product-oriented, efficient, and so that there is a better coordination and monitoring, aligned with the available resources and skills within CIMMYT, and with our numerous public and private partners,” she explains.

Value-for-money farmer impact

An important activity Das coordinated recently is a series of collaborative product profiling workshops with CIMMYT’s partners. Integrating the priorities of the national agricultural research systems and partner seed companies, this exercise reviewed and redefined what maize traits and attributes research should focus on in years to come. After this consultation, partners not only pick up CIMMYT germplasm based on trial data, but they can also verify if it fits with their own profile, to make sure that the traits they want are there. It makes breeding much more targeted and efficient.

“Product profiling has already influenced our research. For instance, all partners mentioned husk cover as a ‘must-have’ trait, because you have less insect attacks and grain spoilage,” Das explains. “Although it was considered a base trait, the breeders did not consider it systematically during their maize line selection and product advancement. Now it is integrated,” she notes.

“Our impact should not be limited to the number of varieties released or the number of papers published, but also how many varieties are picked up by partners, adopted by farmers and scaled up,” Das points out.

Breeders and seed systems specialists have worked together to estimate and track the costs of delivering products. Teams responsible for product profiles can now, through simulation, test different solutions and see what costs could be reduced or adjusted to develop the hybrid.

Das enjoys this type of collaboration. “Managing behavioral change is a key part of my role, being able to work with different teams and cultures, which makes my job so interesting,” she says.

Plates of boiled and roasted maize are displayed for tasting during a farmer participatory varietal selection exercise in Embu, Kenya, in August 2019. Flavors of varieties are very distinct and could explain why some old varieties are still preferably grown by farmers. (Photo: S. Palmas/CIMMYT)
Plates of boiled and roasted maize are displayed for tasting during a farmer participatory varietal selection exercise in Embu, Kenya, in August 2019. Flavors of varieties are very distinct and could explain why some old varieties are still preferably grown by farmers. (Photo: S. Palmas/CIMMYT)

An out-of-the-book thinker in a men’s world

Plant breeding is a male-dominated world but Das is used to fitting in as a minority. Originally from West Bengal, she grew up in Ludhiana, another Indian state and a different culture. She learned genetics and plant breeding at Punjab Agricultural University (PAU) in Ludhiana. Discovering the new field of molecular breeding, at its infancy twenty-five years ago, was an exciting challenge.

At PAU, Das pursued crop improvement research, first in wheat and potato, and later in rice genetics. She received an award from India’s Department of Science and Technology under the Young Scientist Program for her work on jumping genes in basmati rice, aimed at creating shorter and more productive basmati varieties while maintaining the basmati aroma.

Later she joined the International Rice Research Institute (IRRI) to work on the development of Golden Rice, a provitamin A-rich variety, through genetic engineering.

“Being a woman in plant breeding, especially as a breeder, is not that common. Women are not expected to do plant breeding fieldwork, away from the lab and offices. But I did not back off. I did my rice fieldwork in the paddy fields, at 40 degrees, all on my own. I believe that women bring a level of precision that is very important in breeding.”

Bridging public and private sectors

After ten years of public research, she moved to the private seed sector, to learn how seed companies integrate farmers’ needs to their research pipeline, and then channel this research to deliver to millions of farmers. “A big lesson from corporations is the value for money at each stage of their research, and that market research is instrumental to really understand farmers’ needs and guide breeding,” she notes.

After a decade in the private sector, Das was keen to move on and use her experience in the nonprofit sector. Then she joined CIMMYT. “This opportunity of technical program manager was timely. I knew the strengths of CGIAR, having highly educated scientists and the great potential outreach of the research. I knew where crop research could be improved, in converting basic research into demand-driven research.”

“Since my time at IRRI a decade ago, I realized things had moved on in the CGIAR system. Seed systems, product profiling and value chain research are now fully integrated in the Global Maize program. It is a crucial time to be here at CIMMYT. With the CGIAR reform, with the climate emergency, and emerging pests and diseases, we have to be even more inventive and reactive to continue to deliver greater impact,” she concludes.

Breaking Ground: P.H. Zaidi helps Asian farmers get healthy harvests despite climate variability

Written by Matthew O'Leary on . Posted in Features.

Growing up on a rainfed farm in India, P.H. Zaidi learned how smallholder family farmers adapted their farming practices to meet weather challenges, such as dry spells or excessive rain. For the most part, small changes to their crop selection and timing of field operations maintained a wholesome harvest.

As time passed Zaidi witnessed farmers in his hometown and beyond struggling against increasingly extreme and erratic weather events. The Asian tropics have now become hotspots for climate change effects and associated variabilities, said the maize physiologist who works with the Global Maize Program of the International Maize and Wheat Improvement Center (CIMMYT), based in Hyderabad.

“Rainfed farmers produce most of the food for people in Asia, but without sufficient supplemental irrigation systems they are heavily dependent on monsoon rains,” Zaidi said. “Climate variability can be devastating for family farmers who are unable to foresee erratic changes in weather patterns.”

“An extreme weather event can negatively affect household food security and income, which in turn results in a deterioration of capacity to deal with future shocks,” he explained.

Nearly half a billion people in Asia lack access to nourishing food. The Food and Agriculture Organization of the United Nations (FAO) finds climate change-related disasters and a lack of clean water are the main causes of persistent hunger in the region.

Zaidi believes farmers are born innovators and, with the right tools and know-how, they can ensure a healthy harvest despite year-to-year climate variability. He has dedicated his lifework to researching new agricultural technologies that help resource-poor farmers to protect their food and income security.

Stable harvests despite climate change

After getting an undergraduate degree in agricultural science, Zaidi obtained his doctorate at the University of Agriculture Science & Technology in Faizabad, India. He studied how maize physiology interacts with physical stresses, such as severe heat, drought, and excessive moisture. Maize has become an important part of Asian cropping systems, with several countries recording impressive growth rates in maize production and productivity. However, increasing demands — food, feed, and industry — and climate challenges highlight the need for international agricultural research.

In 2002, Zaidi worked as a post-doctoral fellow at CIMMYT in Mexico, where he was mentored by maize abiotic stress experts. He took those research approaches and strategies for breeding stress-resilient maize varieties back home. Working with the Indian government’s maize program, he contributed to developing high-yielding stress-resilient maize for resource-poor maize farmers living in vulnerable agro-ecologies.

With a wealth of knowledge and experience in agricultural systems in Asia, he was employed by CIMMYT as maize physiologist and breeder in 2007. He worked to develop, deploy and scale-out hardy maize varieties that increase yield potential and reduce risk, ensuring a stable harvest despite climate variability. He also developed and standardized screening phenotyping techniques and selection criteria to identify maize germplasm tolerant to stresses including heat, drought and water-logging.

“Through effective collaboration and training, national governments, private seed companies and NGOs are using the varieties with resilient traits in their breeding programs to ensure hardy varieties reach farmers throughout the region,” Zaidi noted.

From 2015 to 2018, a total of 68 such high-yielding stress-resilient maize hybrids were licensed to seed partners in the region, he explained. These partners took them forward for large-scale farmer participatory testing in their respective target ecologies. After extensive testing through the national system, nine stress-resilient maize hybrids have already been released and are being deployed in various countries in Asia. Others will be released soon.

Zaidi has received several awards for his contributions to maize research, including CIMMYT’s Outstanding Scientist Award in 2009.

Ethiopian maize breeders will directly apply knowledge gained from training

Written by Leslie Domínguez on . Posted in News.

Training attendees outside the Rift Valley Hotel in Adama, Ethiopia. (Photo: CIMMYT)

From July 22–26, the Stress Tolerant Maize for Africa (STMA) project organized a training in Adama, Ethiopia to update maize technicians on recent developments in maize research, data collection and seed production. The training was designed to stimulate good breeding programs, good data collection in trial and nurseries, production of better quality seed and development of improved varieties. Around 25 trainees attended, mainly from maize breeding research centers. Similar trainings were conducted in all STMA project countries over the last three and a half years.

CIMMYT staff from Ethiopia, Kenya and Zimbabwe and staff from the Ethiopian Institute of Agricultural Research (EIAR) Bako Research Center delivered training on methodologies and gave practical demonstrations on tablets. Presentations focused on the origin and botany of the maize plant, constraints to maize production in Ethiopia, data collection, breeding for abiotic stresses, new tools for phenotyping, maize lethal necrosis (MLN), and seed quality control.

Mandefro Nigussie, Director General of EIAR, said that the training was important because it addressed data collection. “If we are missing the data, we are missing the investment of the country,” he noted. He recognized CIMMYT’s culture in empowering research centers through trainings. The role of EIAR is to generate, test, disseminate and scale technologies. Therefore, having technicians who are aware of the recent developments in their areas is crucial.

Cosmos Magorokosho, maize breeder and STMA project leader, said that the core components of the training were to give technicians a strong understanding of the basics of maize and the physiology of maize plant. The knowledge they gained from this training will support them during data collection and when breeding for resistance to diseases and pests and improved seed production.

Upon completing five days training, all trainees received certificates along with the presentations and other relevant documents for future reference. CIMMYT maize breeder Dagne Wegary said he appreciated the active participation and dedication of the trainees and the interest they showed to improve their knowledge and skills. He reminded them that this is the start of a long journey and they will have to use the knowledge and skills gained to help farmers produce more and ensure food security. Trainees reflected that the training increased their existing knowledge in maize breeding and helped them to understand the current developments in the area. They said they would directly apply what they have learned and transfer the knowledge to other colleagues working in maize breeding.