Emerging wild virus of native grass bioenergy feedstock is well‐established in the Midwestern USA and associated with premature stand senescence

Abstract

The North American native prairie grass Panicum virgatum (switchgrass) is a primary bioenergy feedstock candidate. Its widespread distribution and genetic diversity enable the possibility of developing this perennial grass for high production in a variety of conditions, including on marginal lands. A critical concern in feedstock development and deployment is the risk of novel pathogen emergence.Here, we investigate the landscape-scale prevalence and epidemiology of a littlestudied North American virus that was first detected in switchgrass and other grasses in bioenergy trials in the US Midwest. Switchgrass mosaic virus (SwMV, Genus Marafivirus, Family Tymoviridae) is transmitted by leafhoppers and is phylogenetically a sister to Maize rayado fino virus, a significant pathogen of maize in parts of the Americas. Our goal was to determine whether SwMV is uniquely limited to specific bioenergy trials or well-established and circulating more broadly. We used molecular diagnostics to quantify naturally occurring SwMV infection in leafhoppers and switchgrass in naturalistic stands throughout a large Midwestern landscape, and quantified leafhopper abundances and stand performance. Our analysis revealed that this apparently wild virus is well-established and widespread. Infection was present at nearly all sites, across diverse landscape contexts, with its prevalence ranging as high as 33%-60%. Infection appeared to

Long-Term Anthropogenic Management and Associated Loss of Plant Diversity Deeply Impact Virome Richness and Composition of Poaceae Communities

“…Alternatively, wild or weedy grasses might serve as a reservoir for crop viruses between cropping cycles. In contrast with crop viruses, only a few studies have begun to evaluate the nature and ecology of non-crop-infecting (“wild”) viruses harbored by grasses ( 20 , 21 ).…”

Pests of selected bioenergy crops

“…The SwMV infection creates straight white, creamy, or yellowish lines and dots in leaves that run parallel all the way to the veins. The virus is distributed through the Southern part of the USA, and it can also be identified in Australia, precisely in New South Wales (Zambrano et al, 2013;Malmstrom et al, 2022).…”