Wild grass breeding approach boosts genetic diversity and resilience of modern wheat
For more than 30 years, wheat breeders at CIMMYT have been using a technique whereby they cross a wild wheat relative with modern durum wheat to produce a variety known as "synthetic hexaploid wheat" — and then cross that into modern bread wheat. The process incorporates the genetic diversity and resilience traits present in the wild wheat relative known as goat grass (Aegilops tauschii) into modern wheat.
A 2019 study in Nature Scientific Reports used state-of-the-art molecular technology to measure the effect of these efforts, and found that genome segments from goat grass are present in more than one in five of elite bread wheat lines developed by CIMMYT.
In fact, 20% of the wheat lines in CIMMYT’s global spring bread wheat breeding program contain an average of 15% of the genome segments from Aegilops tauschii.
“Many breeding programs hesitate to use wild relatives because undesirable genomic segments are transferred in addition to desirable segments,” said Umesh Rosyara, genomic breeder at CIMMYT and first author of the paper. “The study results can help us devise an approach to quickly eliminate undesirable segments while maintaining desirable diversity.”
The common bread wheat we know today arose when an ancient grain called emmer wheat naturally cross-bred with goat grass around 10,000 years ago. During this natural crossing, very few goat grass genes crossed over. Inedible and considered a weed, Aegilops tauschii is an especially valuable source of disease resistance, nutritional quality, heat and drought tolerance, and yield-related traits.
Breeding programs worldwide have used synthetic-derived lines to provide farmers with productive and resilient bread wheat varieties. One example, Chuanmai 42, released in China in 2003, stood as the leading wheat variety in the Sichuan Basin for over a decade.
And, because CIMMYT contributions are present in nearly half the wheat sown worldwide, many of the world’s 2.5 million wheat consumers are also benefiting from healthy and disease-free varieties, thanks to synthetic wheat breeding.
Photo: Aegilops tauschii (synonyms Aegilops squarrosa, Triticum tauschii), a wild goatgrass that was one of the parent species of bread wheat, when it crossed with tetraploid wheats in rare hybridization events in the Fertile Crescent around 10,000 years ago (CIMMYT).
A burning issue: alternatives to burning increase farmers’ profits and cut pollution
A WHEAT authored study published in Science shows that thousands of wheat farmers in northern India could increase their profits if they stop burning their rice straw residue and adopt no-till practices, which could also cut farm-related greenhouse gas emissions by as much as 78% and lower air pollution.
The study, conducted by a global team of eminent agriculture and environmental scientists, was led by researchers from The Nature Conservancy, CIMMYT, the Indian Council of Agricultural Research (ICAR), the Borlaug Institute for South Asia (BISA) and the University of Minnesota.
To quickly and cheaply clear their fields to sow wheat each year, farmers in northern India burn an estimated 23 million tons of straw from their rice harvests. In November 2017, more than 4,000 schools closed in Delhi due to seasonal smog. This smog increases during October and November when fields are burned. It causes major transportation disruptions and poses health risks across northern India, including Delhi, a city of more than 18 million people.
Farmers have alternatives, the study shows. Leaving straw on the soil as a mulch, for example, helps capture and retain moisture and also improves soil quality, according to M.L. Jat, CIMMYT Principal Scientist, cropping systems specialist and a co-author of the study.
Farmers can also sow wheat directly without plowing or burning rice straw by using a tractor-mounted implement known as the “Happy Seeder,” as well as attach straw shredders to their rice harvesters. The Science study shows that Happy Seeder-based systems are on average 10%–20% more profitable than straw burning options.
“Our study dovetails with 2018 policies put in place by the government of India to stop farmers from burning, which includes a US$166 million subsidy to promote mechanization to manage crop residues within fields,” said Priya Shyamsundar, Lead Economist, Global Science, of The Nature Conservancy and first author of the study.
The study demonstrates that it is possible to reduce air pollution and greenhouse gas emissions in a way that is profitable to farmers and scalable.
Photo: The burning of crop residue, or stubble, across millions of hectares of cropland between planting seasons is a visible contributor to air pollution in both rural and urban areas (Dakshinamurthy Vedachalam/CIMMYT).
Discovering the value of “lost” wheat landraces
For more than 8000 years, farmers in Turkey and Afghanistan have been breeding wheat. The work of generations of wheat farmers has resulted in traditional wheat varieties, or landraces, uniquely adapted to the environment and ideally suited for baking nutritious goods. When agriculture became more intensified, many farmers switched to higher-yielding modern varieties, with only small subsistence farmers in remote areas still growing ancient landraces.
Realizing the value and potential of this genetic diversity for developing wheat varieties that are resistant to pests and disease, tolerant to environmental stresses and more nutritious, a team of wheat scientists and breeders set out to rediscover these “lost” varieties. The expedition was made possible by a 5-year project supported by the UN Food and Agriculture Organization’s International Treaty on Plant Genetic Resources for Food and Agriculture. In partnership with the Bahri Dagdas International Agricultural Research Institute in Turkey and the Agricultural Research Institute of Afghanistan, the CIMMYT team collected 162 landraces in Turkey and 25 in Afghanistan.
The team then tested these seeds in the field and selected the best performing varieties, with the help of local farmers. Researchers found that some Afghan landraces were resistant to prevalent rusts and could yield up to 90% as much as modern commercial varieties. To complete the cycle, the team plans to distribute the seeds of these improved landraces to farming communities in the target provinces and offer training on sustainably cultivating their unique landraces to maintain biodiversity in their fields.
By conserving this valuable genetic diversity, future generations can benefit from more resilient wheat production and more nutritious bread.
Photo: Diversity of Turkish wheat landraces collected in 2012 (A. Morgounov/CIMMYT).
Make half your grains whole
Grain-based foods — both whole-grain and refined — are a key part of healthy diets, according to an article co-written by WHEAT scientists.
The article, published in Advances in Nutrition in November 2019, reviewed findings of more than 100 research papers from nutrition and medical journals as well as national health recommendations. It presents evidence for positive health impacts from diverse diets that include not more than 50% carbohydrates and the right mix of grain-based foods.
According to their research, recommendations for grain-based foods need to encourage a healthy number of servings and replacing half of refined-grain foods with whole-grain products.
“Epidemiological studies consistently show that eating three 30-gram portions of whole-grain foods — say, half a cup of oats — per day is associated with reduced chronic disease risk,” said Julie Miller Jones, Professor Emerita at St. Catherine University and first author of the study. “But refined-grain foods — especially staple, enriched or fortified ones of the ‘non-indulgent’ type — also provide key vitamins and minerals that are otherwise lacking in people’s diets.”
The study also calls for clear and unbiased definitions of whole-grain and refined-grain foods. An explainer piece on the WHEAT website attempts to demystify some of these questions.
Photo: A basket contains an assortment of whole, unprocessed, maize and wheat kernels (Alfonso Cortes/CIMMYT).
Experts gather in Turkey to share findings on the diversity and health benefits of wheat
In October 2019, a number of WHEAT scientists including Wheat Breeder Velu Govindan, WHEAT Program Director Hans-Joachim Braun and Maria Itria Ibba, head of CIMMYT’s wheat quality lab presented at the International Conference on Wheat Diversity and Human Health.
The conference, held in Istanbul from Oct 22 - 24, convened experts from around the globe in Istanbul to examine the link between wheat and human health. Although wheat is the second most popular food crop in the world, and a vital source of food and nutrition for humans dating from the earliest days of agriculture, its reputation as a health food has taken a hit in western popular culture in recent times.
Beyond the well-publicized benefits of consuming fiber from whole grain wheat products – including lower risk of coronary disease, diabetes, hypertension, obesity, Type 2 diabetes and colon cancer - scientists at the conference affirmed that wheat also contains compounds such as phenolics, flavonoids and carotenoids that have antioxidant and anti-inflammatory properties, control obesity and reduce the risk of cancer and chronic diseases.
These compounds have also been shown to have a beneficial effect on working memory, can prevent neurological diseases such as Alzheimer’s and Parkinson’s diseases, can delay aging and can prevent Vitamin A deficiency, among many other benefits.
Photo: Durum wheat spikes, Ciudad Obregon, Mexico (Alfonso Cortés/CIMMYT).
Early warning system helps farmers in Ethiopia combat wheat rusts
A new early warning system is helping farmers throughout Ethiopia combat wheat rusts by delivering wheat rust predictions directly to farmer’s phones. The system, which uses field and mobile phone surveillance data together with spore dispersal and environmental suitability forecasts, allows policy makers to forecast a wheat rust outbreak up to a week in advance.
Wheat rusts are devastating fungal diseases that can be dispersed by wind over long distances and can dramatically reduce wheat yields. The early warning system takes near real-time information from wheat rust surveys carried out by the Ethiopian Institute of Agricultural Research (EIAR), regional research centers and CIMMYT using a smartphone app called Open Data Kit (ODK).
This is complemented by crowd-sourced information from the ATA-managed Farmers’ Hotline. The University of Cambridge and the UK Met Office then provide automated 7-day advance forecast models for wheat rust spore dispersal and environmental suitability based on disease presence.
All of this information is fed into an early warning unit that receives updates automatically on a daily basis. In addition to alerts for researchers and farmers, an advisory report is sent out every week to development agents and national authorities.
“If there’s a high risk of wheat rust developing, farmers will get a targeted SMS text alert from the Farmers’ Hotline. This gives the farmer about three weeks to take action,” explained Dave Hodson, principal scientist with CIMMYT and co-author of the research study. The Farmers’ Hotline now has over four million registered farmers and extension agents, enabling rapid information dissemination throughout Ethiopia.
WHEAT scientists and national partners are adapting the early warning system to predict other wheat diseases, such as wheat blast, and piloting it in Bangladesh and Nepal.
Photo: One of the researchers behind the study, Yoseph Alemayehu, carries out a field survey in Ethiopia by mobile phone (Dave Hodson/CIMMYT).
Space data applications for wheat and maize research
An international collaboration of CIMMYT, Wageningen University, the European Space Agency (ESA), and other research and meteorological organizations have been using satellite-sourced weather data to develop practical applications in agricultural and food security.
The ESA collects extremely granular data on weather, churned out at an hourly rate. This data stream generates 22 variables of daily and sub-daily weather data at a 30-kilometer level of accuracy. By incorporating the information from the data sets into field trial data, CIMMYT researchers can specifically analyze maize and wheat cropping systems on a larger scale and create crop models with higher precision, meaning that much more accurate information can be generated from the trials of different crop varieties.
This information will allow researchers to detect side effects related to droughts and heat waves, for example, and the tolerance of maize and wheat lines to those stresses. This in turn will also allow breeders create specific crop varieties for farmers in environments where the impact of climate change is predicted to be more apparent in the near future.
One of the data streams known as AgERA5 provides historical weather variables and is now available on an open access, user-friendly database.
Photo: Weather satellite image (Bernardino Campos, Flickr).
First cohort of Arab Women Leaders in Agriculture graduates
On the eve of International Women’s Day 2019, the International Center for Biosaline Agriculture (ICBA), the Bill & Melinda Gates Foundation, the Islamic Development Bank (IsDB) and WHEAT launched the first edition of the Arab Women Leaders in Agriculture (AWLA) fellowship program.
The first of its kind, the program was designed to empower women researchers in the Middle East and North Africa (MENA) region to spur positive changes in agriculture and food security while addressing the challenges they face in their careers. The MENA region has the lowest share of women researchers in the world – at 17%. The goal of AWLA is to address these gender inequalities and empower women researchers to realize their full potential.
A year later, the first cohort of women researchers from Algeria, Egypt, Jordan, Lebanon, Morocco, and Tunisia celebrated completing the program at a graduation ceremony, fittingly held on International Women’s Day. The cohort included 22 women scientists who completed a 10-month program of interactive modules, face-to-face workshops, coaching and mentoring, and a team-based capstone project.
AWLA’s long-term goal is to improve food security and nutrition in the region through empowering women researchers and helping them realize their full potential. WHEAT Program Manager Victor Kommerell, who attended the graduation ceremony, said “I am confident this cohort of AWLA graduates will have a powerful impact on the future of agriculture in the region.”
Photo: Cake-cutting at the graduation ceremony (ICBA).