McAPRR2 : The Key Regulator of Domesticated Pericarp Color in Bitter Gourd.

Pericarp color is a crucial commercial trait influencing consumer preferences for bitter gourds. However, until now, the gene responsible for this trait has remained unidentified. In this study, we identified a gene () controlling pericarp color via a genome-wide association study (GWAS) utilizing the resequencing data of 106 bitter gourd accessions. exhibits three primary haplotypes: Hap1 is a wild type with a green pericarp, Hap2 is a SA (South Asian) and SEA (Southeast Asia) type with a green pericarp, and Hap3 is primarily a SEA type with a light green pericarp. The haplotype is significantly correlated with both pericarp color and ecological type. Importantly, with the light green pericarp demonstrated premature termination due to a 15 bp sequence insertion. The phylogenetic tree clustered according to pericarp color and ecological type, using SNPs located in the gene and its promoter. High π and π values indicate high nucleotide diversity between wild and SEA types and between SA and SEA types in the gene. The haplotypes, phylogenetic tree, and nucleotide diversity of suggest that has undergone domestication selection. This study identifies as the key gene determining pericarp color in bitter gourds and introduces a novel insight that is subject to domestication selection.