Genome-Wide Association Study Reveals That Is Associated with Pod Stringlessness in Snap Bean ( L.).

Suture strings are a particularly important pod trait that determine the quality and texture of snap beans ( L.). The St locus on chromosome 2 has been described as a major locus associated with suture strings. However, the gene and genetic basis underlying this locus remain unknown. Here, we investigated the suture strings of 138 snap bean accessions across two years. A total of 3.66 million single-nucleotide polymorphisms (SNPs) were obtained by deep resequencing. Based on these SNPs, we identified a strong association signal on Chr02 and a promising candidate gene, Further analysis revealed that the 2 bp deletion in the exon of was significantly associated with stringlessness. Comparative mapping indicated that was a domesticated locus and diverged from during an early stage. Our study provides important insights into the genetic mechanism of suture string formation and useful information for snap bean improvement.