March 14, 2014
Speaker to discuss wheat resistance to Fusarium head blight today
Guihua Bai, USDA Agriculture Research Service, will present "Wheat Resistance to Fusarium Head Blight: What Have We Learned So Far?" at 3:45 p.m. March 13 in 4031 Throckmorton Hall.
The lecture abstract is:
Wheat Fusarium head blight, or FHB, caused primarily by Fusarium graminearum, is one of the most devastating diseases in cereal crops worldwide. Its epidemics result in severe losses not only in grain yield, but also in end-use quality of wheat due to mycotoxins produced by the fungus during infection. Growing resistant cultivars can effectively minimize FHB damage. Worldwide effort has been made in searching for FHB resistance sources, but immunity to FHB has not been found. Germplasm lines with a high level of resistance were identified from China and several other countries, and Sumai 3 and its derivatives from China show the highest level of resistance. Fhb1, a QTL on chromosome 3BS of Sumai 3, has been proven to have the largest effect. Other QTLs were reported from almost all 21 chromosomes of different sources however the resistance effects of these QTLs are not stable when they are used alone. Most U.S. wheat cultivars are highly susceptible, only a few spring wheats have Fhb1. Fhb1 is absent in hard winter wheat grown in the Great Plains. In the past 10 years, my lab has focused on screening of U.S. hard winter wheat for native resistance and Chinese landraces for new QTLs, and pyramiding Fhb1 with U.S. native resistance QTLs in U.S winter wheat backgrounds by marker-assisted backcrossing. We identified some locally adapted germplasm with moderate FHB resistance and QTLs from some of these sources were mapped. For FHB resistance QTLs from Chinese sources, we determined the origin of Fhb1, conducted fine mapping of the QTL, and successfully transferred it to a wide range U.S. adapted winter wheat backgrounds using marker-assisted backcross.