Location: Corn, Soybean and Wheat Quality ResearchTitle: Mapping maize chlorotic mottle virus tolerance loci in the maize 282 association panel
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2022
Publication Date: 4/30/2022
Citation: Ohlson, E.W., Redinbaugh, M.G., Jones, M.W. 2022. Mapping maize chlorotic mottle virus tolerance loci in the maize 282 association panel. Crop Science. 62(4):1497-1510. https://doi.org/10.1002/csc2.20762.
Interpretive Summary: Maize lethal necrosis (MLN) is caused by the synergistic infection of maize by maize chlorotic mottle virus (MCMV) and most commonly a potyvirus. The disease is of significant global importance due to the widespread distribution of the causal viruses of MLN, and has affected the United States, Southeast Asia, South America, and Africa since its initial discovery in the 1970s. Here we report completion of a genomewide association study (GWAS) of tolerance to MCMV in a diverse collection of maize. The GWAS analysis identified several candidate genes with possible roles in facilitating tolerance/susceptibility to MCMV. We also identified a major MCMV tolerance genomic locus on chromosome 10 in maize line CML333. Identification of these genomic loci will help us to better understand mechanisms of virus disease tolerance/susceptibility and facilitate development of MCMV and MLN tolerant maize varieties using traditional and molecular breeding strategies.
Technical Abstract: Maize lethal necrosis (MLN) is a devastating synergistic viral disease of maize caused by maize chlorotic mottle virus (MCMV) plus a virus in the Potyviridae family. The disease has severely impacted maize production in East Africa, Asia, and South America over the past decade and the presence of MCMV and maize infecting potyviruses in the U.S. is of ongoing concern. In this study, we performed a genome-wide association study (GWAS) using the Maize 282 Association Mapping Panel (AMP) to characterize the genetic architecture of host response to MCMV and identify disease tolerant lines. The GWAS analysis detected genomic variants on chromosomes 3, 4, 5, and 8 that were significantly associated with response to MCMV. Several lines in the 282 AMP were highly tolerant of infection, including CML333, one of the parental lines used in the maize nested association mapping (NAM) population. Quantitative trait locus (QTL) analysis of the B73 x CML333 NAM recombinant inbred line (RIL) population revealed an MCMV tolerance locus on chromosome 10. These findings further our understanding of the genetic architecture of MCMV tolerance and will facilitate the development of maize lines, hybrids, and varieties with improved resistance to MLN and MCMV.