Impact of wheat streak mosaic and Triticum mosaic viruses on transmission by the wheat curl mite, Aceria tosichella Keifer

Wheat streak mosaic and triticum mosaic viruses are transmitted to wheat by the wheat curl mite, Aceria tosichella Keifer (WCM). In the Great Plains, these viruses greatly impact winter wheat production and can result in total yield loss in some fields.  Across the region, wheat streak mosaic virus (WSMV) is more prevalent in fields than Triticum mosaic virus (TriMV), but co-infection is frequently observed. WSMV and TriMV show a synergistic relation, worsening disease symptoms when co-infected.  Different mite genotypes have been shown to differentially transmit TriMV when singly infected.  The objective of this study is to establish mite transmission rates of TriMV when co-infected with WSMV. Type 2 WCM were used to  determine transmission rates for four virus treatments: mock, WSMV, TriMV and double infection of WSMV and TriMV. Each treatment had three source plants that were inoculated at 21 days. One week after inoculation, 10 WCM were added to each source plant, and allowed to build up for 3 weeks to provide a mite-virus source for transfer. Individual mites from each source plants were transferred onto each of 10 test plants. Single mite transfer plants were allowed to grow for 21 days before being sampled for virus presence. Virus presence in the source plants and in the single mite transfer test plants was established by ELISA assays in the end of each run. Multiple runs were used as needed to delineate treatment differences.