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New publications: Genome-wide breeding to curtail wheat blast

A recent publication in the journal Frontiers of Plant Science provides results of the first-ever study to test genomic selection in breeding for resistance to wheat blast, a deadly disease caused by the fungus Magnaporthe oryzae that is spreading from its origin in Brazil to threaten wheat crops in South Asia and sub-Saharan Africa.

Genomic selection identifies individual plants based on the information from molecular markers, DNA signposts for genes of interest, that are distributed densely throughout the wheat genome. For wheat blast, the results can help predict which wheat lines hold promise as providers of blast resistance for future crosses and those that can be advanced to the next generation after selection.

In this study, scientists from the International Maize and Wheat Improvement Center (CIMMYT) and partners evaluated genomic selection by combining genotypic data with extensive and precise field data on wheat blast responses for three sets of genetically diverse wheat lines and varieties, more than 700 in all, grown by partners at locations in Bangladesh and Bolivia over several crop cycles.

The study also compared the use of a small number of molecular markers linked to the 2NS translocation, a chromosome segment from the grass species Aegilops ventricosa that was introduced into wheat in the 1980s and is a strong and stable source of blast resistance, with predictions using thousands of genome-wide markers. The outcome confirms that, in environments where wheat blast resistance is determined by the 2NS translocation, genotyping using one-to-few markers tagging the translocation is enough to predict the blast response of wheat lines.

Finally, the authors found that selection based on a few wheat blast-associated molecular markers retained 89% of lines that were also selected using field performance data, and discarded 92% of those that were discarded based on field performance data. Thus, both marker-assisted selection and genomic selection offer viable alternatives to the slower and more expensive field screening of many thousands of wheat lines in hot-spot locations for the disease, particularly at early stages of breeding, and can speed the development of blast-resistant wheat varieties.

Read the full study:
Genomic Selection for Wheat Blast in a Diversity Panel, Breeding Panel and Full-Sibs Panel

The research was conducted by scientists from the International Maize and Wheat Improvement Center (CIMMYT), the Bangladesh Wheat and Maize Research Institute (BWMRI), the Instituto Nacional de Innovación Agropecuaria y Forestal (INIAF) of Bolivia, the Borlaug Institute for South Asia (BISA) and the Indian Council of Agricultural Research (ICAR) in India, the Swedish University of Agricultural Sciences (Alnarp), and Kansas State University in the USA. Funding for the study was provided by the Bill & Melinda Gates Foundation, the Foreign and Commonwealth Development Office of the United Kingdom, the U.S. Agency for International Development (USAID), the CGIAR Research Program on Wheat (WHEAT), the Indian Council of Agricultural Research (ICAR), the Swedish Research Council, and the Australian Centre for International Agricultural Research (ACIAR).

Cover photo: A researcher from Bangladesh shows blast infected wheat spikes and explains how the disease directly attacks the grain. (Photo: Chris Knight/Cornell University)

State-of-the-art maize doubled haploid facility inaugurated in India

Main building of CIMMYT’s maize doubled haploid facility in Kunigal, Karnataka state, India. (Photo: CIMMYT)
Main building of CIMMYT’s maize doubled haploid facility in Kunigal, Karnataka state, India. (Photo: CIMMYT)

On December 3, 2021, the International Maize and Wheat Improvement Center (CIMMYT) and its partners inaugurated a state-of-the-art maize doubled haploid (DH) facility in Kunigal, in India’s Karnataka state. The facility was established by CIMMYT in partnership with the University of Agricultural Sciences, Bangalore (UAS Bangalore), with financial support from the CGIAR Research Program on Maize (MAIZE).

It is the first public sector facility of its kind in Asia, fulfilling a very important need for maize breeding programs in the region. The facility, operated by CIMMYT, will provide DH production services for CIMMYT’s and UAS Bangalore’s breeding programs, as well as for national agricultural research institutions and small- and medium-sized seed companies engaged in maize breeding across tropical Asia. This is expected to result in accelerated development and deployment of a greater number of elite, climate-resilient and nutritionally-enriched maize hybrids in tropical Asia.

DH technology has the potential to enhance genetic gains and breeding efficiency, especially in combination with other modern tools and technologies, such as molecular markers and genomic selection. The facility occupies 12 acres of land at the Agricultural Research Station in Kunigal, in southwestern India. It is expected to produce at least 25,000-30,000 maize DH lines per year.

For more information, and to request these services, visit CIMMYT’s Maize Doubled Haploid Technology website.

R.S. Paroda (center) cuts the ribbon to inaugurate the maize doubled haploid facility in Kunigal, Karnataka state, India. He is flanked by S. Rajendra Prasad (left), vice chancellor of UAS Bangalore and B.M. Prasanna (right), director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize. (Photo: CIMMYT)
R.S. Paroda (center) cuts the ribbon to inaugurate the maize doubled haploid facility in Kunigal, Karnataka state, India. He is flanked by S. Rajendra Prasad (left), vice chancellor of UAS Bangalore and B.M. Prasanna (right), director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize. (Photo: CIMMYT)

Fast-track maize breeding in Asia

R.S. Paroda, who is a Padma Bhushan awardee in India and the chairman of the Trust for Advancement of Agricultural Sciences (TAAS) in New Delhi, thanked CIMMYT for its role in developing the facility. “The maize DH facility will revolutionize hybrid maize programs in both the public and private sectors in Asia, enabling fast-tracked development of climate-resilient and genetically diverse maize hybrids suitable for the rainfed maize-growing areas.”

S. Rajendra Prasad, vice chancellor of UAS Bangalore, appreciated the partnership between his institution and CIMMYT. “The facility will create opportunities to modernize maize breeding programs in India, besides serving as an educational and training hub for young students at the University,” he said. Members of UAS Bangalore Board of Management also participated in the formal opening of the facility.

B.M. Prasanna, director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize (MAIZE), spearheaded the process of establishing this important breeding facility. “Along with similar maize DH facilities in Mexico and Kenya, which respectively serve Latin America and Africa, this third facility for Asia rounds up CIMMYT’s commitment to strengthen tropical maize breeding programs across the globe,” he explained.

Bram Govaerts, CIMMYT’s director general, participated through a recorded video message.

Attending the ceremony were also 150 post-graduate students, faculty from UAS Bangalore, researchers from UAS Raichur and the Indian Institute of Maize Research, CIMMYT maize scientists, and private-sector members of the International Maize Improvement Consortium for Asia (IMIC-Asia).

R.S. Paroda, chairman of the Trust for Advancement of Agricultural Sciences (TAAS) in New Delhi, unveils the inauguration plaque for the maize doubled haploid facility in Kunigal, Karnataka state, India. (Photo: CIMMYT)
R.S. Paroda, chairman of the Trust for Advancement of Agricultural Sciences (TAAS) in New Delhi, unveils the inauguration plaque for the maize doubled haploid facility in Kunigal, Karnataka state, India. (Photo: CIMMYT)

Collaboration networks

A technical workshop titled “Transforming India’s Agriculture and Modernizing Maize Breeding Programs” was held the same day. The workshop featured talks by Paroda on the role of youth in Indian agriculture, Prasanna on modernizing maize breeding and enhancing genetic gain, CIMMYT scientist Vijay Chaikam on maize doubled haploid technology, and CIMMYT breeder Sudha Nair on genomic technologies for maize improvement.

IMIC-Asia held a General Body Meeting soon after the technical workshop, at which B.S. Vivek, maize breeder at CIMMYT, introduced the framework for the third phase of IMIC-Asia. Participants included representatives of the Indian Institute of Maize Research, the All-India Coordinated Maize Improvement Program, and private seed companies with membership in the consortium. Meeting participants expressed a keen interest in utilizing the new doubled haploid facility’s services.

Bringing wild wheat’s untapped diversity into elite lines

A collaboration involving 15 international institutes across eight countries has optimized efforts to introduce beneficial traits from wild wheat accessions in genebanks into existing wheat varieties.

The findings, published in Nature Food, extend many potential benefits to national breeding programs, including improved wheat varieties better equipped to thrive in changing environmental conditions. This research was led by Sukhwinder Singh of the International Maize and Wheat Improvement Center (CIMMYT) as part of the Seeds of Discovery project.

Since the advent of modern crop improvement practices, there has been a bottleneck of genetic diversity, because many national wheat breeding programs use the same varieties in their crossing program as their “elite” source. This practice decreases genetic diversity, putting more areas of wheat at risk to pathogens and environmental stressors, now being exacerbated by a changing climate. As the global population grows, shocks to the world’s wheat supply result in more widespread dire consequences.

The research team hypothesized that many wheat accessions in genebanks — groups of related plant material from a single species collected at one time from a specific location — feature useful traits for national breeding programs to employ in their efforts to diversify their breeding programs.

“Genebanks hold many diverse accessions of wheat landraces and wild species with beneficial traits, but until recently the entire scope of diversity has never been explored and thousands of accessions have been sitting on the shelves. Our research targets beneficial traits in these varieties through genome mapping and then we can deliver them to breeding programs around the world,” Singh said.

Currently adopted approaches to introduce external beneficial genes into breeding programs’ elite cultivars take a substantial amount of time and money. “Breeding wheat from a national perspective is a race against pathogens and other abiotic threats,” said Deepmala Sehgal, co-author and wheat geneticist in the Global Wheat program at CIMMYT. “Any decrease in the time to test and release a variety has a huge positive impact on breeding programs.”

Deepmala Sehgal shows LTP lines currently being used in CIMMYT trait pipelines at the experimental station in Toluca, Mexico, for introgression of novel exotic-specific alleles into newly developed lines. (Photo: CIMMYT)
Deepmala Sehgal shows LTP lines currently being used in CIMMYT trait pipelines at the experimental station in Toluca, Mexico, for introgression of novel exotic-specific alleles into newly developed lines. (Photo: CIMMYT)

Taking into genetic biodiversity

The findings build from research undertaken through the Seeds of Discovery project, which genetically characterized nearly 80,000 samples of wheat from the seed banks of CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA).

First, the team undertook a large meta-survey of genetic resources from wild wheat varieties held in genebanks to create a catalog of improved traits.

“Our genetic mapping,” Singh said, “identifies beneficial traits so breeding programs don’t have to go looking through the proverbial needle in the haystack. Because of the collaborative effort of the research team, we could examine a far greater number of genomes than a single breeding program could.”

Next, the team developed a strategic three-way crossing method among 366 genebank accessions and the best historical elite varieties to reduce the time between the original introduction and deployment of an improved variety.

Sukhwinder Singh (second from left) selects best performing pre-breeding lines in India. (Photo: CIMMYT)
Sukhwinder Singh (second from left) selects best performing pre-breeding lines in India. (Photo: CIMMYT)

Worldwide impact

National breeding programs can use the diverse array of germplasm for making new crosses or can evaluate the germplasm in yield trials in their own environments.

The diverse new germplasm is being tested in major wheat producing areas, including India, Kenya, Mexico and Pakistan. In Mexico, many of the lines showed increased resistance to abiotic stresses; many lines tested in Pakistan exhibited increased disease resistance; and in India, many tested lines are now part of the national cultivar release system. Overall, national breeding programs have adopted 95 lines for their targeted breeding programs and seven lines are currently undergoing varietal trials.

“This is the first effort of its kind where large-scale pre-breeding efforts have not only enhanced the understanding of exotic genome footprints in bread wheat but also provided practical solutions to breeders,” Sehgal said. “This work has also delivered pre-breeding lines to trait pipelines within national breeding programs.”

Currently, many of these lines are being used in trait pipelines at CIMMYT to introduce these novel genomic regions into advanced elite lines. Researchers are collaborating with physiologists in CIMMYT’s global wheat program to dissect any underlying physiological mechanisms associated with the research team’s findings.

“Our investigation is a major leap forward in bringing genebank variation to the national breeding programs,” Singh explained. “Most significantly, this study sheds light on the importance of international collaborations to bring out successful products and new methods and knowledge to identify useful contributions of exotic in elite lines.”

Read the full article:
Direct introgression of untapped diversity into elite wheat lines

Cover photo: A researcher holds a plant of Aegilops neglecta, a wild wheat relative. Approximately every 20 years, CIMMYT regenerates wheat wild relatives in greenhouses, to have enough healthy and viable seed for distribution when necessary. (Photo: Rocío Quiroz/CIMMYT)

Pakistan, India transboundary dialogue imperative to resolve Lahore’s pollution: Amin

During the 26th Conference of Parties (COP26) held in Glasgow, Special Assistant to Pakistan’s Prime Minister on Climate Change Malik Amin Aslam said that a transboundary dialogue on mitigating air pollution was imperative to resolve Lahore’s smog, which is mostly generated by Indian farmers burning crop residues.

Read more: https://dailytimes.com.pk/844672/pakistan-india-transboundary-dialogue-imperative-to-resolve-lahores-pollution-amin/

Less water for better crops

In India, nearly one-sixth of groundwater reserves has been overexploited and almost one-fifth of them is either in critical or semi-critical condition. For a country that relies heavily on groundwater for drinking and irrigation, these statistics are close to a death sentence.

India’s water crisis, however, is not unique in the region. Population growth, coupled with increasing urbanization and industrialization, has made South Asia, one of the most heavily irrigated areas on earth, highly vulnerable to water stress. Moreover, as the effects of climate change are increasingly felt in those countries, agricultural production, even at the current level, may not be sustainable.

Against this background, ensuring that water resources are used efficiently and sustainably is key to meet the world’s growing demand. Over the last decades, traditional systems of irrigation have given way to more efficient drip irrigation systems that deliver the right amount of water and nutrients to the plant’s root zone. But as farm labor shortages become more severe, investing in automated irrigation systems — which promise increased production rates and product quality — will be the only way to ensure the sustainability of agricultural production systems worldwide.

A new article co-authored by a team of researchers from the International Maize and Wheat Improvement Center (CIMMYT) and the Thapar Institute of Engineering and Technology synthesizes the available information related to the automation of drip irrigation systems and explores recent advances in the science of wireless sensor networks (WSN), the internet of things (IoT) and other communication technologies that increase production capacity while reducing costs.

“Bundling both elements — drip irrigation and automation — in water application can lead to large savings in irrigation and boost water efficiency, especially in high water-consuming, cereal-based systems like the Indo-Gangetic Plains,” explained M.L. Jat, a principal scientist at CIMMYT and one of the authors of the review.

Investing in data and youth

Smart irrigation technologies, including sensors and the IoT, allow farmers to take informed decisions to improve the quality and quantity of their crops, providing them with site-specific data on factors like soil moisture, nutrient status, weed pressure or soil acidity.

However, this information is still limited to certain soil types and crops. “To upgrade drip irrigation systems elsewhere, especially in ‘water-stressed’ regions, we need additional agricultural background data in those areas,” Jat pointed out. “That’s the only way we can effectively customize innovations to each scenario, as one size does not fit all.”

Making this data available to and readable by farmers is also essential. Here, young people can become very good allies, as they tend to be more technologically savvy and used to working with large volumes of information. “Not only are they more skilled to integrate agricultural data into decision-making, but they can also help older farmers adopt and trust intelligent irrigation systems,” Jat concluded.

Long-term research platform in Karnal, India, by H.S. Jat, Principal Scientist at ICAR-CSSRI. (Photo: ICAR-CSSRI and CIMMYT)
Long-term research platform in Karnal, India, by H.S. Jat, Principal Scientist at ICAR-CSSRI. (Photo: ICAR-CSSRI and CIMMYT)

Incentives against subsidies

With increasing water shortages worldwide, making the most out of every drop becomes an urgent priority. But in countries where irrigation systems are highly subsidized, farmers may struggle to see this urgency. India, for instance, subsidizes the cost of energy to pump water for farming, thus encouraging smallholders to extract more than they need.

How do we incentivize farmers in these countries to embrace water-efficient technologies?

According to Jat, using the “scientific card” can work with smallholders who, after having farmed for decades, may not change their minds automatically. “These people may be reluctant to accept incentives for water-efficient mechanisms at first, but they will surely be interested in more scientific approaches,” Jat explained, stressing that “the emphasis must be on the science, not on the technology.”

Designing profitable business models can also incentivize producers to embrace more efficient mechanisms. Farmers who have enjoyed irrigation subsidies for decades may not see any profit in trying out new technologies — but what if they are given the chance to become champions or ambassadors of these agricultural innovations? “That brings in a whole new perspective,” Jat said.

Apart from incentivizing farmers, good business models can also draw the attention of large companies, which would bring investment to boost research and innovation in drip irrigation. “More and more businesses are getting interested in smart agriculture and low emission farming, and their inputs can help conceptualize the future of this field,” he observed.

Celebrating 10 years of the Borlaug Institute for South Asia

BISA and CIMMYT gather for a virtual 10 year celebration
BISA and CIMMYT gather for a virtual 10 year celebration.

A decade ago, a foundation was laid with a vision to secure food, nutrition, livelihoods, and the environment in South Asia. The Borlaug Institute of South Asia (BISA) was formed and the principles were set following the path of Norman Borlaug to translate the agrarian challenges into opportunities by collaborating with the International Maize and Wheat Improvement Center (CIMMYT) and the Indian Council of Agricultural Research (ICAR). BISA was established as an independent, non-profit research organization.

BISA anniversary Borlaug statue

To commemorate the 10th anniversary of BISA, Bram Govaerts, Director General, CIMMYT-BISA, gathered BISA staff for a virtual celebration on 5 October 2021. He congratulated BISA colleagues and said “[…] BISA has continued to expand Norman Borlaug’s vision and legacy. It has […] been committed and achieved excellence in science, seeds and partnerships by touching lives of millions of farmers and consumers.”

“Perhaps one of the most impactful outcomes of BISA’s work has been its contribution to build a strong and wide network for evaluating and disseminating new high yielding and climate-resilient wheat varieties for southern Asia in close partnership with ICAR and national agricultural research systems. CIMMYT-BISA has not only contributed towards this but will also make sure that India’s farmers are the happiest. Efforts will and have been made towards their income generation, livelihood for families, a clean environment and building of future agricultural resilience,” he added.

BISA milestones and achievements

Pramod Aggarwal, Regional Program Leader, BISA and CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), gave suggestions for the way forward and BISA’s future collaborations. He said, “It’s time to strengthen BISA and further expand it to other South Asian countries.”

Arun Joshi, Managing Director, BISA, spoke about the achievements of BISA throughout the last decade and about the establishment of the ‘Farms of the Future’. “BISA farms are equipped with state-of-the-art technology. BISA’s no residue burning, efficient resource management, precision phenotyping, climate resilient germplasm, quality seed and capacity development activities are just a few examples of BISA’s successful programs,” he said.

“BISA has been scaling climate smart agriculture technologies not only in Indian villages but to other countries of South Asia, as well, and has supported African colleagues in capacity development.” Joshi recalled the support provided by numerous funding partners, by ICAR (Government of India), state governments (Punjab, Bihar, Madhya Pradesh, Maharashtra), other governmental institutions, CIMMYT’s Board of Trustees and Management Committee team members and different research programs to strengthen BISA.

BISA Ludhiana team gathers for a celebration
BISA’s Ludhiana team gathers for a celebration

Celebrations galore  

In addition to the virtual celebration with the leadership of BISA and CIMMYT, numerous teams scattered across India celebrated the success and fruitful journey of BISA. The teams at BISA farms in Jabalpur (Madhya Pradesh), Pusa (Bihar), and Ludhiana (Punjab) marked the occasion by gathering at a COVID-19-appropriate distance and paid regards to Norman Borlaug and spoke about the objectives and vision of BISA.

BISA Jabalpur team gathers for a celebration
BISA’s Jabalpur team gathers for a celebration

The New Delhi team celebrated by garlanding the statue of Borlaug, that stands in front of the office of BISA based at the National Agriculture Science Complex (NASC).

Capturing the decade-long journey

The ten-year journey of BISA is captured in “A Decade of Research in Borlaug Institute for South Asia (BISA) 2011-2021,” a research highlights report that was unveiled during the virtual celebration and that will soon be available online. Arun Joshi explained that the document encapsulates the spirit of BISA and its achievements throughout the last ten years. Its sixteen themes define the work of BISA and its reach across South Asia.

Special celebratory BISA report to mark its 10 years of success

The report also informs of BISA’s outreach activities throughout the last decade and its impact on climate resilient agriculture. Themes such as ‘Managing Rice Residue Burning’, ‘Climate Smart Village Approach’, ‘Precision Phenotyping in Wheat Breeding’, ‘Developing Improved Crop Insurance Products’, ‘Mainstreaming Gender in Climate-Resilient Agriculture’ reveal how BISA scaled up these approaches with its advanced technology mechanisms. In addition, every theme captures information related to funding and research partners.

Overall, the ten-year report is a robust document which showcases how millions of farmers in South Asia have benefitted from the strong scientific partnership of BISA and national programs.

Taming wheat blast

As wheat blast continues to infect crops in  countries around the world, researchers are seeking ways to stop its spread. The disease — caused by the Magnaporthe oryzae pathotype Triticum — can dramatically reduce crop yields, and hinder food and economic security in the regions in which it has taken hold.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) and other international institutions looked into the potential for wheat blast to spread, and surveys existing tactics used to combat it. According to them, a combination of methods — including using and promoting resistant varieties, using fungicides, and deploying strategic agricultural practices — has the best chance to stem the disease.

The disease was originally identified in Brazil in 1985. Since then, it has spread to several other countries in South America, including Argentina, Bolivia and Paraguay. During the 1990s, wheat blast impacted as many as three million hectares in the region. It continues to pose a threat.

Through international grain trade, wheat blast was introduced to Bangladesh in 2016. The disease has impacted around 15,000 hectares of land in the country and reduced average yields by as much as 51% in infected fields.

Because the fungus’ spores can travel on the wind, it could spread to neighboring countries, such as China, India, Nepal and Pakistan — countries in which wheat provides food and jobs for billions of people. The disease can also spread to other locales via international trade, as was the case in Bangladesh.

“The disease, in the first three decades, was spreading slowly, but in the last four or five years its pace has picked up and made two intercontinental jumps,” said Pawan Singh, CIMMYT’s head of wheat pathology, and one of the authors of the recent paper.

In the last four decades, wheat blast has appeared in South America, Asia an Africa. (Video: Alfonso Cortés/CIMMYT)

The good fight

Infected seeds are the most likely vector when it comes to the disease spreading over long distances, like onto other continents. As such, one of the key wheat blast mitigation strategies is in the hands of the world’s governments. The paper recommends quarantining potentially infected grain and seeds before they enter a new jurisdiction.

Governments can also create wheat “holidays”, which functionally ban cultivation of wheat in farms near regions where the disease has taken hold. Ideally, this would keep infectable crops out of the reach of wheat blast’s airborne and wind-flung spores. In 2017, India banned wheat cultivation within five kilometers of Bangladesh’s border, for instance. The paper also recommends that other crops — such as legumes and oilseed — that cannot be infected by the wheat blast pathogen be grown in these areas instead, to protect the farmers’ livelihoods.

Other tactics involve partnerships between researchers and agricultural workers. For instance, early warning systems for wheat blast prediction have been developed and are being implemented in Bangladesh and Brazil. Using weather data, these systems alert farmers when the conditions are ideal for a wheat blast outbreak.

Researchers are also hunting for wheat varieties that are resistant to the disease. Currently, no varieties are fully immune, but a few do show promise and can partially resist the ailment depending upon the disease pressure. Many of these resistant varieties have the CIMMYT genotype Milan in their pedigree.

“But the resistance is still limited. It is still quite narrow, basically one single gene,” Xinyao He, one of the co-authors of the paper said, adding that identifying new resistant genes and incorporating them into breeding programs could help reduce wheat blast’s impact.

Wheat spikes damaged by wheat blast. (Photo: Xinyao He/CIMMYT)
Wheat spikes damaged by wheat blast. (Photo: Xinyao He/CIMMYT)

The more the merrier

Other methods outlined in the paper directly involve farmers. However, some of these might be more economically or practically feasible than others, particularly for small-scale farmers in developing countries. Wheat blast thrives in warm, humid climates, so farmers can adjust their planting date so the wheat flowers when the weather is drier and cooler. This method is relatively easy and low-cost.

The research also recommends that farmers rotate crops, alternating between wheat and other plants wheat blast cannot infect, so the disease will not carry over from one year to the next. Farmers should also destroy or remove crop residues, which may contain wheat blast spores. Adding various minerals to the soil, such as silicon, magnesium, and calcium, can also help the plants fend off the fungus. Another option is induced resistance, applying chemicals to the plants such as jasmonic acid and ethylene that trigger its natural resistance, much like a vaccine, Singh said.

Currently, fungicide use, including the treatment of seeds with the compounds, is common practice to protect crops from wheat blast. While this has proven to be somewhat effective, it adds additional costs which can be hard for small-scale farmers to swallow. Furthermore, the pathogen evolves to survive these fungicides. As the fungus changes, it can also gain the ability to overcome resistant crop varieties. The paper notes that rotating fungicides or developing new ones — as well as identifying and deploying more resistant genes within the wheat — can help address this issue.

However, combining some of these efforts in tandem could have a marked benefit in the fight against wheat blast. For instance, according to Singh, using resistant wheat varieties, fungicides, and quarantine measures together could be a time-, labor-, and cost-effective way for small-scale farmers in developing nations to safeguard their crops and livelihoods.

“Multiple approaches need to be taken to manage wheat blast,” he said.

Climate-smart strategy for weed management proves to be extremely effective

Rice-wheat cropping rotations are the major agri-food system of the Indo-Gangetic Plains of South Asia, occupying the region known as the “food basket” of India. The continuous rice-wheat farming system is deceptively productive, however, under conventional management practices.

Over-exploitation of resources leaves little doubt that this system is unsustainable, evidenced by the rapid decline in soil and water resources, and environmental quality. Furthermore, continuous cultivation of the same two crops over the last five decades has allowed certain weed species to adapt and proliferate. This adversely affects resource-use efficiency and crop productivity, and has proven to negatively influence wheat production in the Western Indo-Gangetic Plains under conventional wheat management systems.

Studies suggest weed infestations could reduce wheat yields by 50-100% across the South Asian Indo-Gangetic Plains. Globally, yield losses from weeds reach 40%, which is more than the effects of diseases, insects, and pests combined.

Herbicides are not just expensive and environmentally hazardous, but this method of chemical control is becoming less reliable as some weeds become resistant to an increasing number common herbicides. Considering the food security implications of weed overgrowth, weed management is becoming increasingly important in future cropping systems.

How can weeds be managed sustainably?

Climate-smart agriculture-based management practices are becoming a viable and sustainable alternative to conventional rice-wheat cropping systems across South Asia, leading to better resource conservation and yield stability. In addition to zero-tillage and crop residue retention, crop diversification, precise water and nutrient management, and timing of interventions are all important indicators of climate-smart agriculture.

In a recently published 8-year study, scientists observed weed density and diversity under six different management scenarios with varying conditions. Conditions ranged from conventional, tillage-based rice-wheat system with flood irrigation (scenario one), to zero-tillage-based maize-wheat-mung bean systems with subsurface drip irrigation (scenario 6). Each scenario increased in their climate-smart agriculture characteristics all the way to fully climate-smart systems.

At the end of 8 years, scenario six had the lowest weed density, saw the most abundant species decrease dramatically, and seven weed species vanish entirely.  Scenario one, with conventional rice-wheat systems with tillage and flooding, experienced the highest weed density and infestation. This study highlights the potential of climate-smart agriculture as a promising solution for weed suppression in northwestern India.

Read the full study: Climate-smart agriculture practices influence weed density and diversity in cereal-based agri-food systems of western Indo-Gangetic plains

Cover image: Farmer weeding in a maize field in India. (Photo: M. Defreese/CIMMYT)

CIMMYT scientists join 60th All India Wheat and Barley Research Workers’ Meet

Gyanendra Pratap Singh (center), Director of ICAR-IIWBR, presents at the 60th All India Wheat and Barley Research Workers’ Meet. (Photo: Courtesy of ICAR-IIWBR)
Gyanendra Pratap Singh (center), Director of ICAR-IIWBR, presents at the 60th All India Wheat and Barley Research Workers’ Meet. (Photo: Courtesy of ICAR-IIWBR)

The International Maize and Wheat Improvement Center’s (CIMMYT) legacy of work with the Indian Centre for Agricultural Research (ICAR) has once again produced more successful collaborations this year. This solid partnership resulted in the release of new varieties poised to bring new, superior yielding, disease-resistant, high-quality wheat varieties suitable for different production environments to Indian farms.

The National Variety Release Committee announced the release of nine new varieties at the 60th All India Wheat and Barley Research Workers’ Virtual Meet on August 23–24, 2021, hosted by the Indian Institute of Wheat and Barley Research (IIWBR) of ICAR. Of the nine new varieties identified, five were selected by national partners from CIMMYT international trials and nurseries.

At the event, ICAR-IIWBR director Gyanendra Pratap (GP) Singh highlighted the impressive growth trajectory of India’s wheat production, estimated at 109.52 million tons of wheat harvested in 2021, a figure which was 86.53 million tons in 2015 and less than 60 million tons in 1991. Singh highlighted that this success is dependent upon the deployment of superior wheat varieties, bridging yield and information gaps, strengthened seed value chain, supportive government policies and, of course, farmer support to adopt new varieties and technologies.

The CIMMYT-derived varieties announced at the meeting include DBW296, DBW327, DBW332, HUW296 and JKW261. A few days earlier, variety PBW869 was released by the Punjab Agricultural University for growing in Punjab State under conservation agriculture practices.

“An innovative and powerful feature of ICAR-CIMMYT collaboration has been the introduction of long-term (10-month) rotational involvement of Indian young scientists in CIMMYTs breeding program at Mexico as well as in wheat blast screening in Bolivia,” said Arun Joshi, CIMMYT Regional Representative for Asia and Managing Director, Borlaug Institute for South Asia (BISA). “In this way, the breeding program of CIMMYT is an excellent example of joint breeding program with national institutions.”

At the 60th All India Wheat and Barley Research Workers’ Meet, participants highlighted new varieties, production growth and strengthened collaboration. (Photo: CIMMYT)
At the 60th All India Wheat and Barley Research Workers’ Meet, participants highlighted new varieties, production growth and strengthened collaboration. (Photo: CIMMYT)

Beyond expectations

In addition to these important new wheat varieties, some CIMMYT-derived wheat varieties that were released in recent years have now been deemed suitable for regions beyond their initial region of cultivation, showing wide adaptation and yield stability.

Wheat variety DBW222, released in 2020 for the northwestern plain zone, has now been deemed suitable for cultivation in the northeastern plain zone. Similarly, DBW187, which was initially released for the northeastern plain zone, and then for northwestern plain zone as well for early sowing, is now also extended for sowing in the central zone, together representing 25 million hectares of the 31 million hectares of wheat grown in India.

“Farmers prefer these types of varieties that give them flexibility during sowing time, and have high, stable yields, and disease resistance,” GP Singh said at the meeting.

A major achievement discussed at this year’s event was that three of the new varieties — DBW187, DBW303 and DBW222 — achieved record-high demand in Breeders Seed Indent, with first, second and seventh ranks, respectively. This is a reflection and indirect measure of popularity and demand for a variety. IIWBR’s innovative strategy to implement pre-release seed multiplication and create demand for seeds from new varieties has led to a faster turnover of improved varieties.

According to Ravi Singh, Distinguished Scientist and Head of Global Wheat Improvement at CIMMYT, the collaborators are “further expanding our partnership through the support from the Accelerating Genetic Gains in Maize and Wheat (AGG) and zinc-mainstreaming projects, to expand testing of larger sets of elite lines in targeted populations of environments of the four South Asian countries where various IIBWR-affiliated institutions shall expand testing in the 2021–22 crop season.” CIMMYT looks forward to continuing ongoing and new collaborations with the ICAR-IIWBR programs to deliver even faster genetic gain for yield and grain zinc levels in new varieties, he explained.

Speaking during the meeting Alison Bentley, Director of CIMMYT’s Global Wheat Program, highlighted the collaborative efforts underway as part of the AGG project to accelerate breeding progress. “Innovations and discoveries in breeding approaches are being rapidly made — with further investment needed — to quickly and equitably accumulate and deploy them to farmers,” she said.

Seeding happy, cleaning air: Farmers adopting non-burn tech give hope

A paper titled “Fields on fire: Alternatives to crop residue burning in India” and published in the prestigious journal Science found that working with the Happy Seeder—a machine that cuts and lifts the paddy straw while simultaneously sowing the wheat crop and spreading the cut straw as mulch over fields—is not just the least polluting, but also the most scalable solution that can be adopted by farmers en masse.

Read more: https://www.downtoearth.org.in/blog/agriculture/seeding-happy-cleaning-air-farmers-adopting-non-burn-tech-give-hope-77729

A challenge solved

Wheat stalks grow in a in India. (Photo: Saad Akhtar)
Wheat stalks grow in a field in India. (Photo: Saad Akhtar)

For scientists, determining how best to increase wheat yields to meet food demand is a persistent challenge, particularly as the trend toward sustainably intensifying production on agricultural lands grows.

The United Nations projects that the current global population of 7.6 billion will increase to more than 9.8 billion by 2050, making higher grain yield potential vital, particularly as climate instability increases due to global warming. International efforts are also focused on meeting the Zero Hunger target detailed in the UN Sustainable Development Goals before they expire in 2030.

Now, a new landmark research survey on the grain yield potential and climate-resilience of bread wheat (Triticum aestivum L.) has brought scientists a few strides closer to meeting their ambitions.

Grain yield has traditionally been an elusive trait in genomic wheat breeding because of its quantitative genetic control, which means that it is controlled by many genomic regions with small effects.

Challenges also include a lack of good understanding about the genetic basis of grain yield, inconsistent grain yield quantitative trait loci identified in different environments, low heritability of grain yield across environments and environment interactions of grain yield.

To dissect the genetic architecture of wheat grain yield for the purposes of the research, which appeared in Scientific Reports, researchers implemented a large-scale genome-wide association study based on 100 datasets and 105,000 grain yield observations from 55,568 wheat breeding lines developed by the International Maize and Wheat Improvement Center (CIMMYT).

They evaluated the lines between 2003 and 2019 in different sites, years, planting systems, irrigation systems and abiotic stresses at CIMMYT’s primary yield testing site, the Norman E. Borlaug Experimental Research Station, Ciudad Obregon, Mexico, and in an additional eight countries — including Afghanistan, India and Myanmar — through partnerships with national programs.

The researchers also generated the grain-yield associated marker profiles and analyzed the grain-yield favorable allele frequencies for a large panel of 73,142 wheat lines, resulting in 44.5 million data points. The marker profiles indicated that the CIMMYT global wheat germplasm is rich in grain yield favorable alleles and is a trove for breeders to choose parents and design strategic crosses based on complementary grain yield alleles at desired loci.

“By dissecting the genetic basis of the elusive grain-yield trait, the resources presented in our study provide great opportunities to accelerate genomic breeding for high-yielding and climate-resilient wheat varieties, which is a major objective of the Accelerating Genetic Gain in Maize and Wheat project,” said CIMMYT wheat breeder Philomin Juliana.

“This study is unique and the largest-of-its-kind focusing on elucidating the genetic architecture of wheat grain yield,” she explained, “a highly complex and economically important trait that will have great implications on future diagnostic marker development, gene discovery, marker-assisted selection and genomic-breeding in wheat.”

Currently, crop breeding methods and agronomic management put annual productivity increases at 1.2% a year, but to ensure food security for future generations, productivity should be at 2.4% a year.

So, the extensive datasets and results presented in this study are expected to provide a framework for breeders to design effective strategies for mitigating the effects of climate change, while ensuring food-sustainability and security.

The Green Revolution was built on manipulating genes to breed higher-yielding, disease resistant crops. Here’s an ode to one of its pioneers, Sanjaya Rajaram

This tribute to the life and work of Sanjaya Rajaram, one of Norman Borlaug’s most impactful collaborators, also flags CIMMYT’s contribution to improving livelihoods and fostering more productive sustainable maize and wheat farming in low- and middle-income countries.

Read more: https://geneticliteracyproject.org/2021/05/05/the-green-revolution-was-built-on-manipulating-genes-to-breed-higher-yielding-disease-resistant-crops-heres-an-ode-to-one-of-its-pioneers-in-emembering-world-food-prize-laureate-sanjaya-rajaram-s/

Scientist boosted global wheat yield with disease-resistant varieties

Sanjaya Rajaram, a University of Sydney alumnus recognized with the World Food Prize, was a world-renowned wheat breeder and scientist. One of the world’s leading food scientists, he died on February 17 from COVID-19 in Ciudad Obregon, Mexico.

Read more: https://www.smh.com.au/national/scientist-boosted-global-wheat-yield-with-disease-resistant-varieties-20210303-p577cm.html

First complete cytological characterization of the 2NvS translocation

Wheat infected with the blast fungus in Meherpur, Bangladesh, in 2019. (Photo: PLOS Biology)
Wheat infected with the blast fungus in Meherpur, Bangladesh, in 2019. (Photo: PLOS Biology)

As scientists study and learn more about the complicated genetic makeup of the wheat genome, one chromosomal segment has stood out, particularly in efforts to breed high-yielding wheat varieties resistant to devastating and quickly spreading wheat diseases.

Known as the 2NvS translocation, this segment on the wheat genome has been associated with grain yield, tolerance to wheat stems bending over or lodging, and multiple-disease resistance.

Now, thanks to a new multi-institution study led by wheat scientist Liangliang Gao of Kansas State University, we have a clearer picture of the yield advantage and disease resistance conferred by this chromosomal segment for wheat farmers — and more opportunities to capitalize on these benefits for future breeding efforts.

The Aegilops ventricosa 2NvS segment in bread wheat: cytology, genomics and breeding, published in Theoretical and Applied Genetics, summarizes the collaborative effort by scientists from several scientific institutions — including International Maize and Wheat Improvement Center (CIMMYT) head of global wheat improvement Ravi Singh and wheat scientist Philomin Juliana —  to conduct the first complete cytological characterization of the 2NvS translocation.

A rich background

The 2NvS translocation segment has been very valuable in disease-resistance wheat breeding since the early 1990s. Originally introduced into wheat cultivar VPM1 by the French cytogeneticist Gerard Doussinault in 1983 by crossing with a wild wheat relative called Aegilops ventricosa, the segment has been conferring resistance to diseases like eye spot (Pch1 gene), leaf rust (Lr37 gene), stem rust (Sr38 gene), stripe rust (Yr17 gene), cereal cyst (Cre5 gene), root knot (Rkn3 gene) and wheat blast.

The high-yielding blast-resistant CIMMYT-derived varieties BARI Gom 33 and WMRI#3 (equivalent to Borlaug100),released in Bangladesh to combat a devastating outbreak of wheat blast in the region, carry the 2NvS translocation segment for blast resistance.

Earlier research by Juliana and others found that the proportion of lines with the 2NvS translocation had increased by 113.8% over seven years in CIMMYT’s international bread wheat screening nurseries: from 44% in 2012 to 94.1% in 2019. It had also increased by 524.3% in the semi-arid wheat screening nurseries: from 15% in 2012 to 93.7% in 2019. This study validates these findings, further demonstrating an increasing frequency of the 2NvS translocation in spring and winter wheat breeding programs over the past two decades.

New discoveries

The authors of this study completed a novel assembly and functional annotation of the genes in the 2NvS translocation using the winter bread wheat cultivar Jagger. They validated it using the spring wheat cultivar CDC Stanley and estimated the actual size of the segment to be approximately 33 mega base pairs.

Their findings substantiate that the 2NvS region is rich in disease resistance genes, with more than 10% of the 535 high-confidence genes annotated in this region belonging to the nucleotide-binding leucine-rich repeat (NLR) gene families known to be associated with disease resistance.  This was a higher number of NLRs compared to the wheat segment of the Chinese Spring reference genome that was replaced by this segment, adding further evidence to its multiple-disease resistant nature.

In addition to being an invaluable region for disease resistance, the study makes a strong case that the 2NvS region also confers a yield advantage.  The authors performed yield association analyses using yield data on lines from the Kansas State University wheat breeding program, the USDA Regional Performance Nursery —comprising lines from central US winter wheat breeding programs — and the CIMMYT spring bread wheat breeding program, and found a strong association between the presence of the segment and higher yield.

Global benefits

The yield and disease resistance associations of the 2NvS genetic segment have been helping farmers for years, as seen in the high proportion of the segment present in the improved wheat germplasm distributed globally through CIMMYT’s nurseries.

“The high frequency of the valuable 2NvS translocation in CIMMYT’s internationally distributed germplasm demonstrates well how CIMMYT has served as a key disseminator of lines with this translocation globally that would have likely contributed to a large impact on global wheat production,” said study co-author Juliana.

Through CIMMYT’s distribution efforts, it is likely that national breeding programs have also effectively used this translocation, in addition to releasing many 2NvS-carrying varieties selected directly from CIMMYT distributed nurseries.

With this study, we now know more about why the segment is so ubiquitous and have more tools at our disposal to use it more deliberately to raise yield and combat disease for wheat farmers into the future.