Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2006
Publication Date: 12/1/2006
Citation: Divis, L.A., Graybosch, R.A., Peterson, C.J., Baenziger, P.S., Hein, G.L., Beecher, B.S., Martin, T.J. 2006. Agronomic and quality effects in winter wheat of a gene conditioning resistance to wheat streak mosaic virus. Euphytica. Interpretive Summary: Wheat streak mosaic virus is the most damaging pest limiting wheat yields in the western Great Plains. Under severe infections, complete crop loss might occur. Until recently, no effective resistance genes were available. Wheat breeders and geneticists have succeeded in transferring a resistance gene from intermediate wheat-grass, a perennial relative of wheat. The transfer occurred via wide hybridization, and does not involve genetic engineering. Many such transfers of “alien” genetic material have been made in wheat, but frequent negative side effects often are encountered. This paper reports the results of a study designed to determine whether any such effects occur due to the presence of genetic material from intermediate wheat-grass. In the absence of wheat streak infection, no yield penalty was observed. In the presence of a natural viral infection, resistant lines produced 30% more grain than susceptible lines. Thus, the use of this resistant gene in wheat cultivars is both warranted and necessary. Several lines were identified for future testing. Our long-term goal is to provide resistant cultivars to wheat producers in the Great Plains.
Technical Abstract: Wheat streak mosaic virus (WSMV) is one of the most important diseases limiting winter wheat (Triticum aestivum L.) production in the western Great Plains of North America. There is no known effective WSMV resistance within the primary gene pool of wheat. However, a resistance gene (Wsm1) has been transferred to wheat from a perennial relative, intermediate wheat-grass [Thinopyrum intermedium (Host) Barkworth & DR Dewey]. Nebraska-adapted winter wheat lines carrying Wsm1 were used to characterize the effects of this alien introgression on agronomic and quality traits. Sister-lines from six breeding populations were evaluated under virus-free conditions, and under a naturally occurring viral infection. In uninfected locations, no significant difference for grain yield was detected between resistant (R) and susceptible (S) lines, when averaged over populations, but resistant lines had significantly higher test weights. Within populations, significantly higher grain yield was observed only in population 1, while significantly higher test weights occurred in populations 1, 2, 5 and 6. At the infected location, resistant lines were significantly higher in yield in five of six populations. Over all populations, susceptible lines were significantly higher in loaf volume, while resistant lines had higher percent water absorption. Quality effects, however, where not consistent across genetic backgrounds. As the Wsm1 gene provided yield advantages under viral infection, and there was no yield detriment in the absence of the virus, its deployment in hard winter wheat cultivars merits consideration.