What is in this article?:
- While several varieties of wheat have resistance to the virus bred into them, there has been a problem with that genetic resistance breaking down in temperatures above 75 degrees.
- Wheat streak mosaic virus is the most prevalent disease in the southwestern wheat producing region of the U.S.
- Further research might determine that wheat varieties with wheat streak mosaic resistance may be more effective in northern states where wheat is planted later when it is cooler.
THE LEAVES of the Ron L variety of wheat with bred-in resistance to wheat streak mosaic virus show significantly more damage than the leaves of TAM 112 after both were exposed to the same amount of mites and grown under the same environmental conditions, according to Dr. Charlie Rush, Texas AgriLife Research plant pathologist. (Texas AgriLife Research photo by Kay Ledbetter)
“We are tremendously optimistic about what we’ve seen so far, but we know biological systems, by their very nature, are prone to change and that is why it is so important to go back and repeat the study and see if we get similar results in a repeated study,” Rush said. “That will give us confidence that what we are seeing is indeed a response of that particular cultivar.”
Following the second round of the study, Rush will work with other AgriLife Research scientists to try to determine the genetic reason TAM 112 has tolerance to the vector or mite.
“If we were able to identify the actual gene, or genes, responsible for mite resistance, it would be a huge advance to our overall wheat program because cultivars with these genes would have reduced susceptibility to all mite-vectored virus diseases and not just wheat streak mosaic virus,” he said.
“This resistance, combined with the observed drought tolerance of TAM 112, would result in an exceptionally valuable combination for much of the southwestern Great Plains,” Rush said.
He said further research might determine that these wheat varieties with the wheat streak mosaic resistance trait may be more effective in northern states where wheat is planted later when it is cooler.
“We’ve established a collaboration with researchers in Kansas, Nebraska, Oklahoma and Montana to do a regional study on wheat streak and monitor the differences of certain cultivars in general,” Rush said.
Knowing that, he said, they hope to determine why the differences are occurring and develop a disease forecasting risk assessment model for diseases vectored by the mite, including wheat streak mosaic, High Plains disease and triticum mosaic virus.