Location: Hard Winter Wheat Genetics ResearchTitle: A new isolate of wheat streak mosaic virus virulent to Wsm2
|KUMSSA, TADELE - Kansas State University|
|SHOUP RUPP, JESSICA - Kansas State University|
|FELLERS, MADISON - Kansas State University|
|ZHANG, GUORONG - Kansas State University|
Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2019
Publication Date: 1/21/2019
Citation: Kumssa, T.T., Shoup Rupp, J., Fellers, J.P., Fellers, M.C., Zhang, G. 2019. A new isolate of wheat streak mosaic virus virulent to Wsm2. Plant Pathology. 68(4):783-789. https://doi.org/10.1111/ppa.12989.
Interpretive Summary: Plant breeders are constantly breeding new varieties that have new disease resistance genes. However, the popularity of a particular variety can lead to a large area of a single variety to be planted. Thus, a significant pressure is placed on the pathogen to evolve to overcome the resistance gene. This manuscript describes a case where a new strain of Wheat streak mosaic virus has emerged that overcomes a virus resistance gene called Wsm2 in wheat. The virus isolate was characterized for temperature effects, immunochemical reaction, and by genome sequencing. Tests show that the isolate, KSH294, has 17 amino acid changes compared to the standard strain of WSMV. Wheat geneticists need to increase their efforts to identify and utilize new sources of resistance to WSMV.
Technical Abstract: Wheat streak mosaic virus (WSMV) is an economically important pathogen of wheat causing major yield losses in regions where severe infection occurs. To detect the presence of any new virus or new WSMV strain, green foxtail (Setaria viridis L. Beauv.) plants exhibiting virus-like symptoms were sampled in a summer-fallowed wheat field at the Agricultural Research Center-Hays, Kansas State University, Hays, Kansas. These plants were tested serologically for four wheat (Triticum aestivum L.) viruses, WSMV, Triticum mosaic virus (TriMV), Wheat mosaic virus (WMoV: formerly known as High Plains virus) and Foxtail mosaic virus (FoMV). Among 38 plant samples exhibiting virus-like symptoms, four showed strong reactions for WSMV antigen using enzyme-linked immunosorbent assay (ELISA). Viruses from these four samples were isolated and transferred to wheat plants in a growth chamber for pathogenicity testing. Three isolates were avirulent to Wsm2, which provides temperature sensitive resistance to currently prevalent WSMV. However, one isolate, KSH294, overcame Wsm2. Further sequence and phylogenetic analysis of KSH294 confirmed that this isolate is WSMV, but has sequence differences making it distinct from previously identified WSMV isolates included in the phylogenetic analysis.