Relative occurrence and seasonal variations of wheat-infecting viruses in Texas

Wheat is a top 10 agricultural commodity in Texas, but there is limited understanding of the relative occurrence and seasonal variations of wheat-infecting viruses in the state. In this study, high throughput sequencing (HTS) was used to profile the wheat virome across the major production regions in Texas, including the Panhandle, Central, and the Southeast. From spring 2021 to spring 2023, a total of 101 wheat samples were obtained through field sampling visits and diagnostic submissions. Four total RNA pools from a subset of these samples (n = 33: 7-10 per pool) were subjected to HTS, generating complete or partial genomes of eight wheat-infecting viruses, including barley yellow dwarf virus PAV (BYDV-PAV), cereal yellow dwarf virus RPV (CYDV-RPV), High Plains wheat mosaic virus (HPWMoV), triticum mosaic virus (TriMV), brome mosaic virus (BMV), wheat streak mosaic virus (WSMV), wheat Eqlid mosaic virus (WEqMV), and wheat umbra-like virus. Subsequent screening of all 101 samples using virus-specific primers revealed varying incidences of WSMV (74.3%), TriMV (68.6%), BYDV-PAV (13.6%), WEqMV (5.7%), HPWMoV (5.0%), BMV (3.0%), and CYDV-RPV (2.0%) across the three seasons. Mixed infections of two to four viruses were more prevalent (65.3%) compared to single infection (18.8%), with co-infections of two wheat curl mite vectored viruses (TriMV and WSMV) being the most common (40%). The study revealed a greater diversity of wheat-infecting viruses in Texas than previously reported and it confirmed WSMV and TriMV as the main etiological agents of wheat viral diseases in the state.