Genetic Mapping of Fall Armyworm Resistance in Zoysiagrass

Molecular tools have not identifi ed markers for host-plant resistance to fall armyworm [Spodoptera frugiperda (J. E. Smith)], one of the most damaging insect pests in turfgrasses in the southeastern United States. Available quantitative trait loci (QTL) in maize (Zea mays L.) have further not been assessed for utility as comparative markers for the trait across related taxa. This study reports a linkage map of the region conferring major control of fall armyworm resistance in zoysiagrass (Zoysia spp.). One genomic simple sequence repeat (ZgAg136) and one amplifi ed fragment length polymorphism (Zgaw216) were linked to and fl anked the locus for fall armyworm resistance (Zfawr1) by 6.3 and 8.8 cM, respectively. These markers offer immediate value toward marker-assisted selection for fall armyworm resistance in zoysiagrass and potentially across additional important crops. Nonsynteny between the fall armyworm resistance loci in zoysiagrass and maize was indicated by the absence of linkage between 38 candidate markers from maize fall armyworm resistance QTL regions and Zfawr1. As a major-effect locus and putative novel source for fall armyworm resistance gene(s), Zfawr1 is a promising target for further investigation.