QTL Mapping of Whitefly Resistance in Soybean

Whitefly is one of the most damaging insects attacking crops in the world. Resistance to whitefly in soybean [Glycine max (L.) Merr.] has been reported; however, whitefly-resistance genes have not been identified. The objective of this study was to identify quantitative trait loci (QTL) for whitefly resistance in soybean. Two F-2 segregating populations for whitefly resistance were developed. Lines were screened with simple sequence repeats (SSR) scattered across the soybean genome. Phenotypic evaluation was done in Northwest Mexico, where whitefly is a recurrent pest of soybean. Results indicate that whitefly resistance is a polygenic trait, controlled by QTL on different chromosomes. The significant QTL detected were located on chromosomes 12, 18, and 19. In addition, there was evidence that other QTL could be involved in resistance. Fine mapping of the large-effect QTL detected in this study would be helpful to identify tightly linked markers for use in marker-assisted selection (MAS) for whitefly resistance in soybean.