|Seifers, Dallas -|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 17, 2013
Publication Date: June 8, 2013
Repository URL: http://handle.nal.usda.gov/10113/56825
Citation: Seifers, D., Tatineni, S., French, R.C. 2013. Variants of Triticum mosaic virus isolated from wheat in Colorado. Plant Disease. 97:903-911. Interpretive Summary: Triticum mosaic virus (TriMV) is a recently found virus infecting wheat in the Great Plains region, and information on genetic and biological diversity of TriMV isolates is critical to develop effective management strategies. In this study, two field-collected TriMV isolates, C10-492 and C11-775, from Colorado reacted weakly with TriMV antibodies, and differentially infected barley and wheat cv. Mace compared to a well-characterized Kansas isolate of TriMV (TriMV-K). The two field-collected isolates infected barley cv. Gallatin at much reduced levels and induced symptomless infection in wheat cv. Mace at 22 ºC, a temperature-sensitive TriMV-resistant cultivar, compared to efficient infection by TriMV-K, suggesting the existence of biologically different TriMV isolates in the Great Plains region. The two Colorado isolates caused reduced effects on dry weight of wheat plants compared to TriMV-K, suggesting that TriMV isolates differentially react with wheat cultivars. The coat protein sequence of field-collected Colorado isolates is genetically similar to that of TriMV-K except 1 or 2 amino acid differences at the N-terminal region. Our results indicate that care should be taken while screening wheat cultivars with different sources of resistance against TriMV by including a wide variety of TriMV isolates with different biological characteristics.
Technical Abstract: Triticum mosaic virus (TriMV) is a recently discovered virus infecting wheat. We compared the Colorado isolates C10-492 and C11-775 with the 06-123 isolate of TriMV from Kansas (TriMV-K). Comparisons were made using enzyme-linked immunosorbent assay (ELISA), infectivity assay, host range, dry weight (DW), inoculation of ‘Mace’ wheat with temperature-sensitive resistance to Wheat streak mosaic virus and TriMV, and the deduce amino acid (aa) sequence of the coat proteins (CP). Both C10-492 and C11-775 isolates had significantly reduced ELISA values and virus titers in wheat compared to TriMV-K isolate and infected ‘Gallatin’ barley, but at significantly reduced levels compared to TriMV-K. Both Colorado isolates caused symptomless infections in Mace, while TriMV-K isolate caused mosaic symptoms. The aa sequences of the CP differed at the N-terminal region by two and one aa for C10-492 and C11-775, respectively, compared to TriMV-K isolate. The CP sequence of C10-492 differed from C11-775 by one aa. The C10-492 and C11-775 isolates reduced DW significantly in the cv ‘Karl 92’ but considerably less than TriMV-K isolate. For 2137 wheat, the Colorado isolates did not consistently cause significant reduction in DW, while TriMV-K did. The data collectively indicate C10-492 and C11-775 are isolates of TriMV that differ biologically from the TriMV-K isolate on which the species is founded.