Genome-Wide Association Study for Seed Yield of Tepary Bean Using Whole-Genome Resequencing.

Tepary bean ( A. Gray) is a diploid legume species (2 = 2 = 22). It is the most drought- and heat-tolerant crop of the genus . Tepary bean is native to the northern part of Mexico and the south-western part of the U.S. The lack of molecular markers associated with agronomic traits such as 100-seed weight and seed yield limit the development of elite tepary bean cultivars. Therefore, the objectives of this study were to evaluate tepary bean for 100-seed weight and yield, and identify single-nucleotide polymorphism (SNP) markers associated with these traits. A total of 230,000 high-quality SNPs obtained from the whole-genome resequencing of 153 tepary bean accessions were used for this study. For 100-seed weight, a total of 5 and 20 SNPs were found using a mixed linear model (MLM) and compressed mixed linear model (cMLM), respectively. A candidate gene, , encoding the squamosa promoter-binding protein-like (SBP domain) transcription factor family protein was found to be associated with 100-seed weight. For seed yield, a total of one and eight SNPs were identified using an MLM and cMLM, respectively. , encoding for peroxidase family protein, was identified as a candidate gene for seed yield. Both and are likely to be involved in seed development of tepary bean. This is one of the few studies investigating the genetics of 100-seed weight and seed yield in tepary bean.