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Tag: Fusarium head blight

How interactions among hidden enemies and drought effects grain yield and disease severity in bread wheat

Written by Sarah McLaughlin on . Posted in Features.

In nature, plants are simultaneously exposed to a complex system of biotic and abiotic stresses that limit crop yield. The cereal cyst nematode Heterodera filipjevi and dryland crown rot, caused by Fusarium, are important diseases facing cereal production around the world that cause significant yield loss. Yield loss accelerates when those diseases coexist with other abiotic stresses, such as drought.

Hexaploid bread wheat (Triticum aestivum L.) is an essential staple food for a large part of the world’s population, covering around 20% of daily caloric intake in the human diet, with global production at about 670.8 million tons per year, produced over 215.4 million hectares of land worldwide. Therefore, the program studying soil-borne pathogens at the International Maize and Wheat Improvement Center (CIMMYT)’s Turkey office initiated a study to investigate the effect of soil borne diseases (H. filipjevi and Fusarium culmorum) individually and in combination with drought on some morphological and physiological traits in wheat germplasm with different genetic tolerances to the three studied factors.

In this study, yield components included thousand kernel weight, spike weight, seed per spike and total grain yield. Morphological parameters, including plant height, final plant number (seedling emergence), relative water content, leaf chlorophyll content, H. filipjevi cyst number and presence of crown rot, were studied under greenhouse conditions in Turkey.

The main findings of the study showed that the interaction among water stress, F. culmorum and H. filipjevi increased the damage on the wheat parameters studied when compared with each stress applied alone. One of the most significant damages was seen in high seedling mortality under the three combined stresses (56% seedling death rate), which indicates the damage on wheat yield might occur at the seedling stage rather than later stages. This reduces plant density per area, which was ultimately responsible for low grain yield produced. The known dryland disease, crown rot, caused by F. culmorum, was significantly pronounced under water-stressed conditions.

In all studied parameters, the lowest damage was found among the resistant cultivars to biotic or abiotic stresses. This underscores the importance of wheat breeding programs to develop resistant germplasm, and reminds farmers to replace their old, susceptible varieties with new, resistant ones.

Based on our intensive experience in the CWANA region, most wheat growers basically do not recognize soil borne pathogens as a problem. In fact, most of them do not know that what nematode or soil fungal species are in their fields affecting yield. The term “hidden enemy” perfectly applies to the problems in the region and beyond. Integrated pest management (IPM) is, however, not practiced in the entire region and soil borne pathogen-induced yield losses are simply accepted.

We can conclude from this study that yield reduction in wheat due to soil borne pathogens could be lessened by improving and understanding the concept of IPM in the region where the practice of winter mono-culturing of wheat is the norm. Management of cereal soil-borne pathogens, especially cereal cyst nematode and crown rot, could involve an integrated approach that includes crop rotation, genetic resistance, crop nutrition and appropriate water supply.

Cover photo: Four different test crops show different stresses: T1V8 = Drought, T2V8 = Drought and Nematodes, T3V8 = Drought and fungus, T4V8 = Drought and nematode and fungus together. (Credit: CIMMYT)

CIMMYT and JAAS representatives signed the agreement to establish a screening facility for Fusarium head blight in Nanjing, China.

New international partnership to identify and develop resistance to dangerous wheat disease

Written by Marcia MacNeil on . Posted in Press releases.

CIMMYT and JAAS representatives signed the agreement to establish a screening facility for Fusarium head blight in Nanjing, China.
CIMMYT and JAAS representatives signed the agreement to establish a screening facility for Fusarium head blight in Nanjing, China.

The CGIAR Research Program on Wheat (WHEAT), led by the International Maize and Wheat Improvement Center (CIMMYT) and the International Center for Agriculture in the Dry Areas (ICARDA), recently announced a partnership with the Jiangsu Academy of Agricultural Sciences (JAAS) in China to open a new screening facility for the deadly and fast-spreading fungal wheat disease Fusarium head blight, or FHB.

The new facility, based near the JAAS headquarters in Nanjing, aims to capitalize on CIMMYT’s world-class collection of disease-resistant wheat materials and the diversity of the more than 150,000 wheat germplasm in its Wheat Germplasm Bank to identify and characterize genetics of sources of resistance to FHB and, ultimately, develop new FHB-resistant wheat varieties that can be sown in vulnerable areas around the world.

“The participation of JAAS in the global FHB breeding network will significantly contribute to the development of elite germplasm with good FHB resistance,” said Pawan Singh, head of wheat pathology for CIMMYT.

“We expect that in 5 to 7 years, promising lines with FHB resistance will be available for deployment by both CIMMYT and China to vulnerable farmers, thanks to this new station.”

Fusarium head blight is one of the most dangerous wheat diseases. It can cause up to 50% yield loss and produce severe mycotoxin contamination in food and feed, which affects farmers in the form of increased health care and veterinary care costs, and reduced livestock production.

Even consuming low to moderate amounts of Fusarium mycotoxins may impair intestinal health, immune function and fitness. Deoxynivalenol (DON), a mycotoxin the fungus inducing FHB produces, has been linked to symptoms including nausea, vomiting, and diarrhea. In livestock, Fusarium mycotoxin consumption exacerbates infections with parasites, bacteria and viruses — such as occidiosis in poultry, salmonellosis in pigs and mice, colibacillosis in pigs, necrotic enteritis in poultry and swine respiratory disease.

In China, the world’s largest wheat producer, Fusarium head blight is the most important biotic constraint to production.

The disease is extending quickly beyond its traditionally vulnerable wheat growing areas in East Asia, North America, the southern cone of South America, Europe and South Africa — partly as a result of global warming, and partly due to otherwise beneficial, soil-conserving farming practices such as wheat-maize rotation and reduced tillage.

“Through CIMMYT’s connections with national agricultural research systems in developing countries, we can create a global impact for JAAS research, reaching the countries that are expected to be affected the expansion of FHB epidemic area,” said Xu Zhang, head of Triticeae crops research group at the Institute of Food Crops of the Jiangsu Academy of Agricultural Sciences.

The new collaborative effort will target Fusarium head blight research but could potentially expand to research on other wheat diseases as well. Wheat blast, for example, is a devastating disease that spread from South America to Bangladesh in 2016. Considering the geographical closeness of Bangladesh and China, a collaboration with CIMMYT, as one of the leading institutes working on wheat blast, could have a strong impact.

Although the platform is new, the two institutions have a longstanding relationship. The bilateral collaboration between JAAS and CIMMYT began in early 1980s with a shuttle breeding program between China and Mexico to speed up breeding for Fusarium head blight resistance. The two institutions also conducted extensive germplasm exchanges in the 1980s and 1990s, which helped CIMMYT improve resistance to Fusarium head blight, and helped JAAS improve wheat rust resistance.

Currently, JAAS and CIMMYT are working on Fusarium head blight under a project funded by the National Natural Science Foundation of China called “Elite and Durable Resistance to Wheat Fusarium Head Blight” that aims to deploy resistance genes/QTL in Chinese and CIMMYT germplasm and for use in wheat breeding.

This research is supported by CGIAR Fund Donors.

INTERVIEW OPPORTUNITIES:

Xinyao He, Wheat Pathologist and Geneticist, Global Wheat Program, CIMMYT. x.he@cgiar.org, +52 55 5804 2004 ext. 2218

FOR MORE INFORMATION, CONTACT THE MEDIA TEAM:

Marcia MacNeil, Communications Officer, CGIAR Research Program on Wheat. m.macneil@cgiar.org, +52 55 5804 2004 ext. 2070.

Rodrigo Ordóñez, Communications Manager, CIMMYT. r.ordonez@cgiar.org, +52 55 5804 2004 ext. 1167.

ABOUT CIMMYT:

The International Maize and Wheat Improvement Center (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 support from national governments, foundations, development banks and other public and private agencies. For more information, visit staging.cimmyt.org.

ABOUT JAAS:

Jiangsu Academy of Agricultural Sciences (JAAS), a comprehensive agricultural research institution since 1931, strives to make agriculture more productive and sustainable through technology innovation. JAAS endeavors to carry out the Plan for Rural Vitalization Strategy and our innovation serves agriculture, farmers and the rural areas. JAAS provide more than 80% of new varieties, products and techniques in Jiangsu Province, teach farmers not only to increase yield and quality, but also to challenge conventional practices in pursuit of original ideas in agro-environment protection. For more information, visit home.jaas.ac.cn/.