Experimental host and vector ranges of the emerging maize yellow mosaic polerovirus

Authors: Ohlson, Erik; Kharti, Nitika; Wilson, Jennifer - Jenny

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2023
Publication Date: 4/30/2024
Citation: Ohlson, E.W., Khatri, N., Wilson, J.R. 2024. Experimental host and vector ranges of the emerging maize yellow mosaic polerovirus. Plant Disease. 108(5):1246-1251. https://doi.org/10.1094/PDIS-06-23-1124-RE.
DOI: https://doi.org/10.1094/PDIS-06-23-1124-RE

Interpretive Summary: Maize yellow mosaic virus (MaYMV) is a virus that has been frequently found in corn, other cereal crops, and weedy grasses over the past decade. First reported in China in corn plants collected in 2013, the virus has since been found in Africa and the Americas. MaYMV can reduce corn growth and yields by 10-30% and is spread by multiple species of aphids. Understanding what crops and grasses MaYMV infects and which insect species spread the virus is critical for developing disease management strategies. We tested whether MaYMV can infect ten cereal crops and nine other grasses as well as the ability of five insect species to transmit the virus between plants. We discovered four additional agronomically important crops, oats, foxtail millet, barley and rye can be infected by MaYMV in addition to the previously reported crops including corn, wheat, sorghum and broom millet. We also discovered four additional weedy grass species that are susceptible to MaYMV, including ryegrass, switchgrass and green foxtail, which are widespread in the U.S. We are the first to discover that the greenbug aphid is an insect capable of transmitting MaYMV, meaning the virus can be spread by at least three different insect species. These findings improve our understanding of potential sources of MaYMV and means of its spread. Growers will benefit from this information by using it to inform appropriate crop rotation, pest control and weed management strategies leading to reduced disease and improved yields.

Technical Abstract: Maize yellow mosaic virus (MaYMV) is an emerging polerovirus that has been detected on maize and other cereal crops and weedy grass species in Asia, Africa, and the Americas. Disease symptoms in maize include prominent leaf tip reddening and stunting. Infection by MaYMV has been reported to reduce plant growth and yields by 10-30% in some instances. In this study, an experimental host range for MaYMV among agronomically important cereal crops and common grasses was established. Additional aphid species were assessed as potential vectors for MaYMV and their transmission efficiencies were determined. Here we report oats, foxtail millet, barley, and rye as new experimental cereal crop hosts of MaYMV in addition to the previously reported corn, sorghum, and wheat. Four of the nine other grass species evaluated were also identified as suitable experimental hosts for MaYMV. Interesting, no visible symptoms were present in any of the infected hosts besides the susceptible maize control. Vector range studies identified the greenbug aphid, Schizaphis graminum, as a new vector of MaYMV, though transmission efficiency was only 10-20%, much lower than the previously reported Rhopalosiphum maidis and R. padi vectors. Given MaYMV’s global ubiquity, ability to evade detection, and broad host range, further characterization of yield impacts and identification of viable control strategies are desirable.