Location: Hard Winter Wheat Genetics Research Unit
Title: Resistance to Wheat streak mosaic virus identified in synthetic wheat lines Authors
|Shoup Rupp, Jessica -|
|Simon, Zachary -|
|Gilett-Walker, Beth -|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 4, 2014
Publication Date: N/A
Interpretive Summary: Wheat streak mosaic virus (WSMV) is a serious wheat pathogen that causes stunting, with yellow streaks in the leaves, while reducing the yield of the crop. Unfortunately, there are few resistance genes available for WSMV. Bread wheat is a natural hybrid of three wild species and breeders can utilize wild relatives of wheat that have resistance genes. However, this is difficult to do because wild relatives do not easily cross pollinate with common wheat. So, researchers at the International Center for Maize and Wheat Improvement (CIMMYT) in Mexico developed a set of lines called synthetic hexaploids which are hybrids of a wild species, Aegilops tauschii, and durum wheat. We screened these for WSMV resistance. More than 400 synthetic lines were screened and four were found to have temperature-sensitive resistance to WSMV. These four lines can now be used as parental lines to transfer the resistance into wheat lines adapted to the Great Plains.
Technical Abstract: Wheat streak mosaic virus (WSMV) is a significant pathogen in wheat that causes economic loss each year. WSMV is typically controlled using cultural practices such as the removal of volunteer wheat. Genetic resistance is limited. Until recently, no varieties have been available with major resistance genes to WSMV. Two resistance genes have been derived from Thinopyrum intermedium through chromosome engineering, while a third gene was transferred from bread wheat through classical breeding. New sources of resistance are needed and synthetic wheat lines provide a means of accessing genetic variability in wheat progenitors. A collection of wheat synthetic lines was screened for WSMV resistance. Four lines, 07-SYN-27, -106, -164, and -383 had significant levels of resistance. Resistance was effective at 18 oC and virus accumulation was similar to the resistant control, WGGRC50 containing Wsm1. At 25 oC, resistance was no longer effective and virus accumulation was similar to the susceptible control, Tomahawk. Resistant lines are now being backcrossed to bread wheat lines to move the genes into a more adapted genetic background.