|Byamukama, E -|
|Wegulo, S -|
|Hein, G -|
|Baenziger, P -|
|French, R -|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 20, 2013
Publication Date: January 3, 2014
Repository URL: http://handle.nal.usda.gov/10113/58253
Citation: Byamukama, E., Tatineni, S., Hein, G.L., Graybosch, R.A., Baenziger, P.S., French, R.C., Wegulo, S.N. 2014. Quantification of yield loss caused by Triticum mosaic virus and Wheat streak mosaic virus in winter wheat under field conditions. Plant Disease. 98:127-133. Interpretive Summary: Wheat curl mite-transmitted Triticum mosaic virus (TriMV) and Wheat streak mosaic virus (WSMV) are economically important viruses infecting wheat in the Great Plains region of the United States. Because WSMV and TriMV are transmitted by a common vector (wheat curl mite), double infection of wheat cultivars by these two viruses has been reported in commercial fields. Previously, we reported that co-infection of wheat by TriMV and WSMV can exacerbate yield losses due to synergistic interaction between these two viruses under greenhouse conditions. In this study, we quantified the effects of single (WSMV or TriMV) and double infections (WSMV and TriMV) on yield (grain yield, spikes/m2, kernels/spike, and 1000-kernel weight) in wheat cvs. Millennium and Mace under field conditions. In wheat cv. Millennium, single and double infections caused significant yield losses with the greatest reductions occurring in the doubly infected plants. In contrast, single and double infections in Mace exhibited only mild effects on yield under field conditions. These data suggest that wheat cv. Mace is resistant to both WSMV and TriMV, and double infection of susceptible winter wheat (cv. Millennium) by WSMV and TriMV intensifies yield losses under field condition.
Technical Abstract: Triticum mosaic virus (TriMV) and Wheat streak mosaic virus (WSMV) infect winter wheat in the Great Plains region of the United States. The two viruses are transmitted by wheat curl mites, which also transmit High Plains virus. In a field study conducted in 2011 and 2012, winter wheat cultivars Millennium (WSMV-susceptible) and Mace (WSMV-resistant) were mechanically inoculated with TriMV, WSMV, TriMV+WSMV, or sterile water at the two-leaf growth stage. Cholorophyll meter (soil plant analysis development [SPAD] readings, area under the SPAD progress curve (AUSPC), grain yield (= yield), yield components (spikes/m2, kernels/spike, 1000-kernel weight), and aerial dry matter were determined. In cv. Millennium, all measured variables were significantly reduced by single or double virus infections, with the greatest reductions occurring in the double-infection treatment. Among the yield components, the greatest reductions occurred in spikes/m2. In cv. Mace, only AUSPC was significantly reduced by the TriMV+WSMV treatment in 2012. There was a significant (P = 0.05), negative linear relationship between SPAD readings and day of year in all inoculation treatments in cv. Millennium and in the TriMV+WSMV treatment in cv. Mace. There were significant (P = 0.05), positive linear relationships between yield and SPAD readings and between yield and aerial dry matter in cv. Millennium but not in cv. Mace. The results from this study indicate that under field conditions, (i) cv. Mace, a WSMV-resistant cultivar, is also resistant to TriMV and (ii) double infection of winter wheat by TriMV and WSMV exacerbates symptom expression and yield loss in a susceptible cultivar.