|Chang, Hao-xun - University Of Illinois|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2017
Publication Date: 5/15/2017
Citation: Chang, H., Hartman, G.L. 2017. Characterization of insect resistance loci in the USDA soybean germplasm collection using genome-wide association studies. Frontiers in Plant Science. 8:670. doi: 10.3389/fpls.2017.00670.
Interpretive Summary: Genetic resistance is a key strategy for managing soybean insect pests. In past decades, soybean germplasm has been characterized for resistance to many different insect pests. Even though genes for resistance have been incorporated into some breeding lines and commercial cultivars, high-throughput techniques to associate regions of soybean chromosomes with insect pest resistance have been lacking. Recently, genome-wide association studies using high-quality genetic markers and information on plant responses to insect pests have become powerful tools to identify chromosomal regions in unrelated germplasm lines with insect pest resistance. The objective of our study was to use the data in the United States Department of Agriculture, Agricultural Research Service, Germplasm Resources Information Network (USDA-ARS-GRIN) on responses to insect pests and a set of high quality genetic markers to identify chromosomal regions associated with insect pest resistance. In this study we report the association of genetic markers with resistance to four insect pests. The manuscript presents a review and a global view of soybean resistance loci against multiple insect pests, and discusses the power and the challenges of genome-wide association to discover insect pest resistance utilizing the USDA-ARS-GRIN soybean database. This information is important to scientists interested in research on managing insect pests through host-plant resistance.
Technical Abstract: Management of insects that cause economic damage to yields of soybean mainly rely on insecticide application. Sources of resistance in soybean plant introduction (PIs) to different insect pests have been reported, and some of these resistance sources, like for the soybean aphid (SBA) have been used to develop resistant soybean cultivars for soybean producers. With the availability of SoySNP50K and the statistical power of genome-wide association studies, we integrated phenotypic data for beet armyworm, Mexican bean beetle (MBB), potato leafhopper (PLH), SBA, soybean looper (SBL), velvetbean caterpillar (VBC), and chewing damage caused by unspecific insects for a comprehensive understanding of insect resistance in the United States Department of Agriculture Soybean Germplasm Collection. We identified significant single nucleotide polymorphisms for MBB, PLH, SBL, and VBC, and we highlighted several leucine-rich repeat-containing genes and myeloblastosis transcription factors within the high linkage disequilibrium region that surrounds the significant SNPs. Specifically for soybean resistance to PLH, we found the PLH locus is close but distinct to a locus for soybean pubescence density on chromosome 12. The results provide genetic support that pubescence density may not directly link to PLH resistance. This study offers a novel insight of soybean resistance to four insect pests and reviews resistance mapping studies for major soybean insects.