Location: Hard Winter Wheat Genetics Research Unit
2012 Annual Report
Work continued on breeding for resistance to Ug99 stem rust of wheat. Three-gene or four-gene combinations of resistance genes Sr22, Sr26, Sr35, and Lr34 are being moved into adapted hard winter wheat backgrounds. Resistance genes Sr32, Sr33, Sr39, Sr40, Sr50, and Sr53 are being backcrossed singly into an adapted hard winter wheat line. Germplasm lines with reduced linkage drag will be identified and genes will eventually be combined in sets of three or four.
A mapping population for durable, minor gene, slow-rusting resistance was developed from the spring wheat line, Kingbird, and a susceptible hard white winter wheat. The population was tested in the field for the first time in 2012. As expected, resistance segregated as a quantitative character. In the next year, work will begin on mapping the locations of the stem rust resistance genes in Kingbird.
Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are significant pathogens affecting wheat production in Kansas, but there are few resistance genes available for breeding. We are exploring the use of RNA interference (RNAi) to provide resistance to these two viruses. Two homozygous wheat lines with RNAi constructs for the coat protein of each virus have been greenhouse tested for resistance to WSMV and TriMV this year. All four lines were resistant to their respective virus. Future work will include molecular characterization of the transgenic lines.