Characterization of an Ohio isolate of brome mosaic virus and its impact on growth, development, and yield of soft red winter wheat

Authors: HODGE, BRIAN - The Ohio State University; SALGADO, JORGE - The Ohio State University; PAUL, PIERCE - The Ohio State University; Stewart, Lucy

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2018
Publication Date: 4/22/2019
Citation: Hodge, B.A., Salgado, J.D., Paul, P., Stewart, L.R. 2019. Characterization of an Ohio isolate of brome mosaic virus and its impact on growth, development, and yield of soft red winter wheat. Phytopathology. 103(6):1101-1111. https://doi.org/10.1094/pdis-07-18-1282-RE.
DOI: https://doi.org/10.1094/pdis-07-18-1282-RE

Interpretive Summary: An Ohio isolate of Brome mosaic virus (BMV), identified in surveys for virus in Ohio wheat over several growing seasons, was studied for impact on wheat yield and yield components. Despite the expectation and reports that BMV has minimal yield impact on wheat, our data show that both early (fall) and late (spring) inoculations of soft red winter wheat cultivars resulted in significant yield impact in field inoculation experiments replicated over two growing seasons (2016 and 2017). These results provide yield impact data and information on potential impact of this Ohio BMV isolate on two cultivars at different inoculation time points, informing pathologists and growers of impact and potential need to manage BMV.

Technical Abstract: Brome mosaic virus (BMV) is a cereal virus that is generally thought to have little economic impact on crop production. However, studies examining the impact of this disease on wheat have been restricted to greenhouse experiments, with little information available regarding its impact on growth and productivity under field conditions. Following the detection of BMV at high prevalence in Ohio wheat fields, the pathogen was isolated, characterized, and tested for its impact on soft red winter wheat (SRWW). The genome of one of the isolates (BMV-OH) was sequenced using next generation and Sanger sequencing techniques and found to be > 99% identical to a BMV-Fescue isolate. BMV-OH was then used in field experiments conducted during the 2016 and 2017 growing seasons to quantify its effect on SRWW grain yield and development when inoculated at Feekes 1, 5, 8 and 10. Two to four cultivars were inoculated at each of the tested growth stages. Cultivar and timing of inoculation had statistically significant (P < 0.05) main and interaction effects on grain yield, wheat growth, and components of yield. Compared to non-inoculate or mock-inoculated checks, BMV-OH reduced grain yield by up to 61% when inoculated at Feekes 1, and by as much as 36 and 31% for inoculations at Feekes 8 and 10, respectively. The magnitude of the yield reduction varied among cultivars and was associated with reductions in grain size and weight or plant population, depending on the growth stage at which the crop was infected. These findings suggest that BMV could be having an impact on wheat productivity in Ohio and will serve as the basis for more large-scale investigations of the effects of this virus in commercial fields.