Construction of a high-density genetic map for yardlong bean and identification of ANT1 as a regulator of anthocyanin biosynthesis.

Because its long, tender pods supply essential proteins, vitamins, and fibers to humans, yardlong bean () is a commonly consumed vegetable, especially in Southeast Asia. To provide insights into the genetic bases of key agricultural traits in yardlong bean, we here created a high-density bin-map with 2084 bin markers using 514 227 SNPs from a recombinant-inbred line (RIL) population. Quantitative trait loci (QTL) mapping was carried out to identify loci associated with anthocyanin content (ANT), vitamin E content (VE), total soluble protein content (TSP), pod length (PL), hundred-seed weight (HSW), seed length and width (SL and SW, respectively), and seed coat color (SCC). In total, 20 related QTLs were isolated, explaining 7.58-56.03% of the phenotypic variation. Of these, five major QTLs (, , , , and ) were detected in 2020, 2021, and the combined environment, explaining 11.96-56.03% of the phenotypic variation. was identified as a causal gene for the QTL , which regulated anthocyanin content; was highly expressed in immature purple pods but barely detectable in white pods. overexpression in tobacco leaves and yardlong bean hairy roots resulted in purple coloration as a result of anthocyanin accumulation. These findings suggested that was a key regulator of anthocyanin accumulation in yardlong bean. Our results lay a firm foundation for target agricultural trait improvement and clarification of the genetic mechanisms underlying agricultural traits in yardlong bean.