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.

In an excellent example of scientific collaboration spanning borders and generations, Mustapha El-Bouhssini, entomologist at the International Centre for Agricultural Research in the Dry Areas (ICARDA), screened wheat breeding lines from the International Maize and Wheat Improvement Center (CIMMYT) under glasshouse infestations of Russian wheat aphid (Diuraphis noxia), a major global pest of wheat. At least one of the lines, which were developed through crosses of wheat with related crop and grass species, showed high levels of resistance.

Scientists at CIMMYT began research on sources of RWA resistance for wheat in the early 1990s. Good sources of resistance from rye were accessed via wide crosses that combined major portions of both crop’s chromosomes, in collaborative work led by Adam J. Lukaszewski, University of California, Riverside.

“In our experiments, we did an initial screening with one replication and then a replicated test with a Pavon line and the check,” said El-Bouhssini.

Pavon is a semi-dwarf wheat variety developed by Sanjaya Rajaram, former CIMMYT wheat director and 2014 World Food Prize laureate. The version of Pavon referred to by El-Bouhssini had been crossed with rye by Lukaszewski and entered CIMMYT’s wheat genetic resource collections; the check was a popular high-yielding variety with no resistance to Russian wheat aphid.

Pavon had been used by Lukaszewski and colleagues as a model variety for wide crosses to transfer pest and disease resistance to wheat from its distant relatives. More recently Leonardo Crespo-Herrera, CIMMYT wheat breeder, pursued this research for his doctoral studies. It was he who provided a selection of wide-cross lines to El-Bouhssini.

“Resistance to pests in wheat is a valuable trait for farmers and the environment,” said Crespo-Herrera. “It can protect yield for farmers who lack access to other control methods. For those with access to insecticides, it can minimize their use and cost, as well as negative impacts on the environment and human health.”

 

As of 29 April, Dr. Jacques Wery, Professor of Agronomy and Agricultural Systems of the University of Montpellier, will begin serving as Deputy Director General for Research for ICARDA. In his new role, he will provide scientific and managerial leadership in setting priorities, planning, implementing, and monitoring a cohesive research agenda aligned with ICARDA’s strategic direction and results framework.

Click here to read the full announcement on the ICARDA web page.

 

31 January 2018
by Laura Strugnell

A commentary published on 30 January in the leading science journal Nature Plants highlights the importance of an ancient grass species for wheat breeding. The commentary was sparked by the recent publication of a reference genome from Aegilops tauschii, also called goat grass.

Bread wheat was created some 10,000 years ago by a natural cross of more simple, primitive wheats with a sub-species of goat grass. As such, goat grass genes constitute a major component of the very large wheat genome. The sequencing of goat grass DNA opens the way for wheat breeders to apply a number of advanced approaches to improve the speed and precision of wheat breeding for important traits that may be found in the goat grass segment of the wheat genome.

The International Maize and Wheat Improvement Center (CIMMYT) and the International Centre for Agricultural Research in the Dry Areas (ICARDA) have produced many wheat x grass crosses, recreating the original, natural cross but using other goat grass species and thus greatly expanding wheat’s diversity. Wheat lines derived from those crosses have since been used in breeding programs worldwide and have helped farmers to boost yields by up to 20 percent. Goat grass is known for being highly adaptable and disease tolerant, so the crosses endow wheat with similar qualities. Varieties from these crosses make up over 30 percent of international seed stores.

Researchers expect that the sequencing of this grass species’ DNA will facilitate advanced approaches such as “speed breeding” – a technique that uses controlled variables to achieve up to seven rounds of wheat crops in one year. This will help allow wheat breeding to keep up with the rising global demand for the crop and to address the challenges of new, virulent diseases and more extreme weather.

Read the Nature Plants article: The goat grass genome’s role in wheat improvement. 2018. Rasheed, A., Ogbonnaya, F.C., Lagudah, E., Appels, R., He, Z. In: Nature Plants.

Using non-GM molecular breeding techniques, ICARDA’s scientists developed a set of durum wheat varieties that can withstand up to 40°C heat along the Senegal River basin. If scaled up, the technology offers potential to fight hunger and help farmers adapt to rising temperatures.

Click here to read the report on the ICARDA web page.

With generous funding from the Australian Centre for International Agricultural Research (ACIAR) over the last 15 years, Afghanistan research organizations and the International Maize and Wheat Improvement Center (CIMMYT) have helped supply Afghan farmers with improved varieties and farming practices to boost production of maize and wheat.

“As of 2012, the start of the most recent phase of ACIAR-funded work, Afghanistan partners have developed and released 12 high-yielding and disease resistant bread wheat varieties, as well as 3 varieties of durum wheat, 2 of barley and 3 of maize,” said Rajiv Sharma, a senior wheat scientist at CIMMYT and country liaison officer for CIMMYT in Afghanistan.

Sharma spoke at a workshop, which took place on August 28, with partners from the Agricultural Research Institute of Afghanistan (ARIA) of the country’s Ministry of Agriculture, Irrigation & Livestock (MAIL). The event was organized to review accomplishments and facilitate MAIL’s takeover of all activities, when the project ends in October 2018.

“The pedigrees of all new varieties feature contributions from the breeding research of CIMMYT and the International Winter Wheat Improvement Programme based in Turkey, both responsible for introducing more than 9,000 new wheat and maize lines into the country since 2012,” Sharma added. The International Winter Wheat Improvement Programme (IWWIP) is operated by Turkey, CIMMYT, and ICARDA (the International Center for Agricultural Research in the Dry Areas).

Sharma noted that CIMMYT’s presence in Afghanistan, which includes support for breeding research and training for local scientists, dates back several decades and that the latest achievements with ARIA and other partners and ACIAR support include:

• The delineation of wheat agro-climatic zones.
• Forecasting climate change impacts on the Afghan wheat crop.
• Strategizing to raise wheat production.
• Characterization of Afghanistan’s wheat genetic resource collection.
• Training abroad for 64 Afghan researchers and in-country for 4,000.
• Launching research on wheat hybridization.
• In direct partnership with farmers, more than 1,800 farmer field demonstrations, 80 field days, and introduced machinery like seed drills and mobile seed cleaners.
• Shared research on and promotion of conservation agriculture, genomic selection, wheat bio-fortification, quality protein maize, climate change, crop insurance and wheat blast resistance and control.

In good years Afghan farmers harvest upwards of 5 million tons of wheat, the country’s number-one food crop, but in some years annual wheat imports exceed 1 million tons to satisfy domestic demand, which exceeds 5.8 million tons.

Multiple partners map avenues to fortify cereal farming

The workshop attracted 45 participants representing ARIA, MAIL, ICARDA, CIMMYT, Michigan State University, ACIAR, the Food and Agriculture Organization of the United Nations (FAO), the Embassy of Australia, and several provincial Directorates of Agriculture, Irrigation & Livestock (DAIL) of Afghanistan.

Among other participants, Mahboobullah Nang, Director of Seed Certification, and Akbar Waziri, Director of the Cereal Department, both from MAIL, offered the Ministry’s support for the continuation of CIMMYT’s longstanding efforts in Afghanistan, particularly in breeding and varietal testing and promotion.

Representing ACIAR, Syed Mousawi commended capacity development activities organized by CIMMYT since the 1970s, which have raised the quality of crop research in Afghanistan and provided a vital link to the global science community over the years.

Participants also recommended extending CIMMYT outreach work, offering training in extension, introducing advanced technologies, and support for and training in varietal maintenance, conservation agriculture, experimental designs, research farm management, data analysis and data management.

The hottest on record, 2016 also marked another year that ICARDA has been on the frontlines of agricultural sustainability and innovation. The 2016 annual report highlights the organization’s efforts to provide farmers throughout the drylands with the latest tools, resources, and training to ensure that their livelihoods — and food security — are resilient to the increasing onslaught of climate change.

Click here to view or download a copy of the full report.

The challenge for WHEAT is no less than to raise the productivity, affordability and quality of wheat and wheat-based foods for 2.5 billion resource-poor consumers in 89 countries today, as well as meeting rising demand from a world population expected to surpass 9 billion by mid-century.

Click here to see how 2016 activities and advances in science and partnerships are empowering farmers and catalyzing wheat value chains, amid political instability, fragile food markets and warmer and erratic weather.

MONTPELLIER, France (June 5, 2017) – The 2017 Olam Prize for Innovation in Food Security was awarded to the “Adapting durum wheat varieties to the Senegal Basin for food security” project led by Filippo Maria Youssef Bassi, durum wheat breeder at the International Center for Agricultural Research in the Dry Area (ICARDA).

By Matthew O’Leary/CIMMYT

EL BATAN, Mexico (May 30,2017)– In an effort to stamp out hidden hunger, scientists are calling for support to make zinc-biofortification a core trait in the world’s largest wheat breeding program.

At least 2 billion people around the world suffer from micronutrient deficiency, or hidden hunger, which is characterized by iron-deficiency anemia, vitamin A and zinc deficiency.

Zinc deficiency remains a crucial health issue in sub-Saharan Africa and South Asia. As a key nutrient in red meat, zinc deficiency is prevalent in areas of high cereal and low animal food consumption.