In February 2019 filmmaker Chris Knight of International Programs at Cornell University’s College of Agriculture and Life Sciences visited the Kenya Agricultural and Livestock Research Organization – Food Crops Research Institute (KALRO – FCRI) research station in Njoro, Kenya.  Wanting to visually capture how Cornell is working with CIMMYT and a global partnership of more than 25 countries to protect the world’s wheat from diseases and the stress of climate change, he produced the short film Protecting the World’s Wheat – Delivering Genetic Gain in Kenya .

The film features East Africa, a center of genetic diversity for wheat stem rust, a fungal pathogen that causes significant yield losses worldwide. To combat this, partner countries test more than 50,000 experimental wheat lines against stem rust in Kenya every year at the Njoro research station to ensure that newly released wheat varieties will be resistant to emerging virulent races of the stem rust fungus as they evolve and spread.

Farmers and scientists have been fighting stem rust since the domestication of wheat thousands of years ago. This brilliant dance between humans and nature will likely never stop, but by working together we can stay one step ahead of this pesky pathogen. As Ruth Wanyera, Principal Research Scientist at KALRO stated, “(Stem rust) is running, and we’re also running. It’s running, and we’re also running. We have to do something to make sure there’s food in the table. That is where my motivation is. Let’s do something. Let’s feed the world. Let there be food for people to eat, or for people to survive.”

As a part of a global network to combat the Ug99 race of wheat stem rust, the International Maize and Wheat Improvement Center (CIMMYT), in collaboration with Cornell University and the Kenya Agricultural and Livestock Research Organization (KALRO), established a stem rust phenotyping platform in Njoro, Kenya in 2008.

Under the aegis of the Durable Rust Resistance in Wheat (DRRW) project and with support from the Bill & Melinda Gates Foundation, the platform evaluates the resistance of germplasm against Ug99 from 25 to 30 countries around the world.

Mandeep Randhawa — a wheat breeder and geneticist — joined CIMMYT’s Global Wheat Program in 2015 and took responsibility as manager of the Njoro wheat stem rust phenotyping platform in 2017.

In the following Q&A —  based on an interview with Chris Knight of Cornell University’s Borlaug Global Rust Initiative — Mandeep talks about his role and his thoughts on global wheat production and the fight against Ug99.

Q: Could you describe the significance of the work that goes on here to global wheat production and global food security with respect to wheat?

A: CIMMYT has a global mandate to serve developing countries in terms of developing new wheat and maize varieties. Under the CIMMYT-Kenya shuttle breeding program, seed of about 2000 segregated populations are imported and evaluated against stem rust races for two seasons in Njoro, and spikes from resistant plants of each cross are selected, harvested and threshed together. Then, seed from each cross is shipped back to Obregon [the Campo Experimental Norman E. Borlaug in Obregon, Mexico].

In Obregon, CIMMYT selects for resistance against leaf rust and stem rust diseases using the local rust races. Plants are selected in Obregon and about 90,000 to 100,000 plants harvested. After grain selection, 40,000 to 50,000 small plots are grown in other testing sites in Mexico where another round of selections are made. About 10,000 lines undergo first year yield trials in Obregon, and are tested for stem rust resistance here in Kenya for two seasons.

After combining data from the various test sites with the stem rust score from Kenya, the top performing lines (about 10%) undergo second year yield tests in Obregon.

These high-yielding lines are distributed internationally to our national partners, and are available to the public for use in breeding program for release as potential varieties.  

I believe that it is helpful to develop new varieties with higher yield to benefit mankind.

Q: Twenty years have now passed since Ug99 was first identified. One way to frame the story is how high the stakes were at the time. If we didn’t have this screening platform, if we hadn’t come together around trying to fight Ug99, what would have happened to global wheat production?

This is a good question. We have done so much for the last 10 years using this platform. We are developing high-yielding lines that are rust resistant, which are benefiting not only the world’s wheat community, but will eventually benefit the farmer and help raise global wheat production. If we had not acted at the right time, we would not be able to know the effect of these emerging races and how they’re evolving and affecting the world of our wheat. If we didn’t have proper surveillance on rusts, we wouldn’t be able to know what types of stem rust races are evolving.

If we did not have this platform, we would see wheat varieties simply killed by stem rust and we wouldn’t have enough resources to tackle it today.

Now we are at a place where several Ug99-resistant genes have been identified – they are very useful in the breeding programs.

There are two types of resistance. One is race specific resistance and another is race non-specific resistance. If you deploy race specific resistance, there is always the fear that these genes will be rendered ineffective because of the evolution of new races. It has been seen in East Africa with the wheat varieties Robin and Digelu that were rendered susceptible with the emergence of virulent strains of wheat stem rust pathogen. To avoid sudden breakdown of resistance, we at CIMMYT are working to identify, characterize and combine race non-specific type of rust resistance sources. Race non-specific resistance is considered more durable. At least four to five genes need to be combined in one cultivar to have a stronger immunity or resistance.

Q: Let’s talk a little bit about the future. We’ve made a lot of progress, we’ve developed this platform, we brought a community of more than 25 countries together to work on this problem. What do we need to do in the next 20 years?

Stem rust was considered a disease prevalent in warmer environments, but now we can see that races have also evolved in Europe, which means that stem rust is adapting to cooler climates. In the near future, or in the next 20 years, I think we have to continue testing wheat germplasm at this platform to develop high-yielding rust resistant varieties that can be released in different countries, which will be helpful to the global wheat community. And globally speaking, it will be helpful to increase our wheat production.

Q: That’s really exciting. Thinking about the number of wheat lines that are screened here, how many wheat lines are screened here every year, and how many countries do we serve?

When the platform initially formed, my predecessors struggled a lot. It was very hard to plant wheat here. Now we have progressed in the last ten years to reach a level that we can test about 25,000 lines in one season. We have two seasons here in Kenya: one is the off-season starting from January to April/May, and then the main season starts from June and goes to the end of October. During these two seasons, about 50,000 lines per year can be tested at this platform. About 25 to 30 countries are benefitting by testing their germplasm here.

Q: We not only need to cultivate the wheat, we need to cultivate the next generation of scientists. So can you talk about the trainings that are run here on a regular basis? People from all over the world come here to learn about rust pathology and wheat breeding, right?

In the last 10 years, we have been implementing capacity building where young scientists are coming to attend a stem rust training course every year, in September and October. Every year we train about 20 to 30 young scientists from national programs in East Africa, South Asia, the Middle East and South America. Every year Dr. Bob McIntosh — he’s a living legend, an encyclopedia of rust resistance – comes over to Njoro to give field demonstrations, teach new technologies, how we can work together, how you can evaluate rust in the field and in the greenhouse. And in addition, a team of scientists from CIMMYT, ICARDA and Cornell University have been coming to provide lectures on genetics and breeding for rust resistance and rust surveys every year for the last 10 years. We have trained more than 200 scientists.

Q: Do you have a final word of motivation for all of the collaborators around the world who are supporting and helping together to achieve these goals?

We have seen in the last two decades of work here that rust never sleeps, as Dr. Norman Borlaug said. It continues to evolve, and the different races keep on moving around and tend to survive on wheat without any resistance. Not only in east Africa: you can see the stem rust is already in Europe – in Sicily, in Germany and the UK. And there is a risk to South Asia as well, as the wind is blowing toward the bread wheat producing area there. If stem rust reaches there, it can cause a huge loss to global wheat production.

So, I request that countries’ national agriculture research systems contact us: me or Ruth Wanyera, the wheat rust pathologist in KALRO  if they want to test or evaluate their material at this platform. We are more than happy to evaluate the germplasm from any country.

Mandeep can be reached at m.randhawa@cgiar.org

By Mike Listman

Rapidly emerging and evolving races of wheat stem rust and stripe rust disease—the crop’s deadliest scourges worldwide—drove large-scale seed replacement by Ethiopia’s farmers during 2009-14, as the genetic resistance of widely-grown wheat varieties no longer proved effective against the novel pathogen strains, according to a new study by the International Maize and Wheat Improvement Center (CIMMYT).

Based on two surveys conducted by CIMMYT and the Ethiopian Institute of Agricultural Research (EIAR) and involving more than 2,000 Ethiopian wheat farmers, the study shows that farmers need access to a range of genetically diverse wheat varieties whose resistance is based on multiple genes.

After a severe outbreak in 2010-11 of a previously unseen stripe rust strain, 40 percent of the affected farm households quickly replaced popular but susceptible wheat varieties, according to Moti Jaleta, agricultural economist at CIMMYT and co-author of the publication.

“That epidemic hit about 600,000 hectares of wheat—30 percent of Ethiopia’s wheat lands—and farmers said it cut their yields in half,” Jaleta said. “In general, the rapid appearance and mutation of wheat rust races in Ethiopia has convinced farmers about the need to adopt newer, resistant varieties.”

The fourth most widely grown cereal after tef, maize, and sorghum, wheat in Ethiopia is produced largely by smallholder farmers under rainfed conditions. Wheat production and area under cultivation have increased significantly in the last decade and Ethiopia is among Africa’s top three wheat producers, but the country still imports on average 1.4 million tons of wheat per year to meet domestic demand.

National and international organizations such as EIAR, CIMMYT, and the International Centre for Agricultural Research in the Dry Areas (ICARDA) are working intensely to identify and incorporate new sources of disease resistance into improved wheat varieties and to support the multiplication of more seed to meet farmer demand.

New wheat varieties have provided bigger harvests and incomes for Ethiopia farmers in the last decade, but swiftly mutating and spreading disease strains are endangering wheat’s future, according to Dave Hodson, CIMMYT expert in geographic information and decision support systems, co-author of the new study.

“In addition to stripe rust, highly-virulent new races of stem rust are ruining wheat harvests in eastern Africa,” he explained. “These include the deadly Ug99 race group, which has spread beyond the region, and, more recently, the stem rust race TKTTF.”

As an example, he mentioned the case of the wheat variety Digalu, which is resistant to stripe rust and was quickly adopted by farmers after the 2010-11 epidemic. But Digalu has recently shown susceptibility to TKTTF stem rust and must now be replaced.

“In rust-prone Ethiopia, the risks of over-reliance on a widely-sown variety that is protected by a single, major resistance gene—Digalu, for example—are clearly apparent,” he added. “CIMMYT and partners are working hard to replace it with a new variety whose resistance is genetically more complex and durable.”

Hodson said as well that continuous monitoring of the rust populations in Ethiopia and the surrounding region is essential to detect and respond to emerging threats, as well as to ensure that the key pathogen races are used to screen for resistance in wheat breeding programs.

Hodson and partners at the John Innes Centre, UK, and EIAR are leading development of a handheld tool that allows rapid identification of disease strains in the field, instead of having to send them to a laboratory and lose precious time awaiting the results.

CIMMYT and partners are also applying molecular tools to study wheat varietal use in Ethiopia. “There are indications that yields reported by farmers were much lower than official statistics, and farmer recollections of varietal names and other information are not always exact,” Hodson explained. “We are analyzing results now of a follow-up study that uses DNA fingerprinting to better document varietal use and turnover.”

The authors would like to acknowledge the Standing Panel for Impact Assessment (SPIA) for financing, the Diffusion and Impacts of Improved Varieties in Africa (DIIVA) project that supported the first survey in 2011, and Cornell University, the Bill & Melinda Gates Foundation, and United Kingdom’s Department for International Development (DFID) through the Durable Rust Resistance in Wheat (DRRW, now called Delivering Genetic Gain in Wheat) project for support for the second survey in 2014.

By Laura Strugnell and Mike Listman

CIUDAD OBREGÓN, Mexico (CIMMYT) – As more than 200 wheat science and food specialists from 34 countries gathered in northwestern Mexico to address threats to global nutrition and food security, 9 outstanding young women wheat scientists among them showed that this effort will be strengthened by diversity.

Winners of the Jeanie Borlaug Laube Women in Triticum (WIT) Early Career Award joined an on-going wheat research training course organized by the International Maize and Wheat Improvement Center (CIMMYT), 21-23 March.

“As my father used to say, you are the future,” said Jeanie Borlaug Laube, daughter of the late Nobel Peace Prize laureate, Dr. Norman E. Borlaug, and mentor of many young agricultural scientists. Speaking to the WIT recipients, she said, “You are ahead of the game compared to other scientists your age.”

Established in 2010 as part of the Delivering Genetic Gain in Wheat (DGGW) project led by Cornell University, the WIT program has provided professional development opportunities for 44 young women researchers in wheat from more than 20 countries.

The award is given annually to as many as five early science-career women, ranging from advanced undergraduates to recent doctoral graduates and postdoctoral fellows. Selection is based on a scientific abstract and statement of intent, along with evidence of commitment to agricultural development and leadership potential.

Women who will change their professions and the world

Weizhen Liu, a 2017 WIT recipient and postdoctoral researcher at Cornell University, is applying genome-wide association mapping and DNA marker technology to enhance genetic resistance in tetraploid and bread wheat to stripe rust, a major global disease of wheat that is quickly spreading and becoming more virulent.

“I am eager to join and devote myself to improving wheat yields by fighting wheat rusts,” said Liu, who received her bachelors in biotechnology from Nanjing Agricultural University, China, in 2011, and a doctorate from Washington State University in 2016. “Through WIT, I can share my research with other scientists, receive professional feedback, and build international collaboration.”

Mitaly Bansal, a 2016 WIT award winner, currently works as a Research Associate at Punjab Agricultural University, India. She did her PhD research in a collaborative project involving Punjab Agricultural University and the John Innes Centre, UK, to deploy stripe and leaf rust resistance genes from non-progenitor wild wheat in commercial cultivars.

“I would like to work someday in a position of public policy in India,” said Bansal, who received the Monsanto Beachell-Borlaug scholarship in 2013. “That is where I could have the influence to change things that needed changing.”

Networking in the cradle of wheat’s “Green Revolution”

In addition to joining CIMMYT training for a week, WIT recipients will attend the annual Borlaug Global Rust Initiative (BGRI) technical workshop, to be held this year in Marrakech, Morocco, from 14 to 17 April, and where the 2018 WIT winners will be announced.

The CIMMYT training sessions took place at the Norman Borlaug Experiment Station (CENEB), an irrigated desert location in Sonora State, northwestern Mexico, and coincided with CIMMYT’s 2018 “Visitors’ Week,” which took place from 19 to 23 March.

An annual gathering organized by the CIMMYT global wheat program at CENEB, Visitors’ Week typically draws hundreds of experts from the worldwide wheat research and development community. Participants share innovations and news on critical issues, such as the rising threat of the rust diseases or changing climates in key wheat farmlands.

Through her interaction with Visitors’ Week peers, Liu said she was impressed by the extensive partnering among experts from so many countries. “I realized that one of the most important things to fight world hunger is collaboration; no one can solve food insecurity, malnutrition, and climate change issues all by himself.”

A strong proponent and practitioner of collaboration, Norman E. Borlaug worked with Sonora farmers in the 1940-50s as part of a joint Rockefeller Foundation-Mexican government program that, among other outputs, generated high-yielding, disease-resistant wheat varieties. After bringing wheat self-sufficiency to Mexico, the varieties were adopted in South Asia and beyond in the 1960-70s, dramatically boosting yields and allowing famine-prone countries to feed their rapidly-expanding populations.

This became known as the Green Revolution and, in 1970, Borlaug received the Nobel Peace Prize in recognition of his contributions. Borlaug subsequently led CIMMYT wheat research until his retirement in 1979 and served afterwards as a special consultant to the Center.

When a new, highly virulent race of wheat stem rust, Ug99, emerged in eastern Africa in the early 2000s, Borlaug sounded the alarm and championed a global response that grew into the BGRI and associated initiatives such as DGGW.

“This is just a beginning for you, but it doesn’t end here,” said Maricelis Acevedo, a former WIT recipient who went on to become the leader of DGGW. Speaking during the training course, she observed that many WIT awardees come from settings where women often lack access to higher education or the freedom to pursue a career.

“Through WIT activities, including training courses like this and events such as Visitors’ Week and the BGRI workshop,” Acevedo added, “you’ll gain essential knowledge and skills but you’ll also learn leadership and the personal confidence to speak out, as well as the ability to interact one-on-one with leaders in your field and to ask the right questions.”

CIMMYT is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR Research Programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives generous support from national governments, foundations, development banks and other public and private agencies.

Funded by the Bill & Melinda Gates Foundation and the UK’s Department for International Development (DFID) under UK aid, the DGGW project aims to strengthen the delivery pipeline for new, disease resistant, climate-resilient wheat varieties and to increase the yields of smallholder wheat farmers.