Date of this Version
de Oliveira, C.F. 2013. Impact of Wheat streak mosaic virus and Triticum mosaic virus on transmission by Aceria tosichella Keifer (Eriophyidae) and virus epidemiology in wheat. M.S. Thesis. University of Nebraska- Lincoln
The wheat curl mite (WCM), Aceria tosichella Keifer, transmits a complex of viruses, Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV) and Wheat mosaic virus (WMoV), to wheat, Triticum aestivum, in the Great Plains. Co-infection of wheat by these viruses is frequently observed, increasing disease severity and yield loss.
Current genetic work classifies WCM populations into two genotypes, Type 1 and Type 2. It has been shown that different mite genotypes are able to transmit viruses at varying rates. WCM-virus relations are very specific and can impact vector biology. In this study, the primary objective was to determine if co-infection of wheat by WSMV+ TriMV has an impact on each virus transmission rate by the WCM Type 1 and Type 2. An additional objective was to establish the impact of double viral infections on the biology of the mites and virus dispersal in the field.
Using a series of transmission studies, it was determined that Type 1 WCMs do not transmit TriMV even in the presence of WSMV. Type 2 WCMs feeding on wheat infected with both viruses, have reduced WSMV transmission when compared to mites feeding on singly inoculated plants. However, TriMV transmission is increased when mites feed on wheat infected by both viruses.
Mite counts from the field indicated that mites feeding on WSMV infected plants had the highest populations, followed by the control, WSMV+TriMV and TriMV. In field conditions, WSMV incidence was reduced when Type 2 WCM were exposed to source plants with WSMV+TriMV. TriMV incidence was not different between mites feeding on single or double infected plants. These findings enhance the understanding of WCM virus complex epidemiology.
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