QTL mapping and identification of candidate genes for anthocyanidin accumulation in Salvia miltiorrhiza flowers.

This article focuses on elucidating the genetic and molecular mechanisms regulating flower color in Salvia miltiorrhiza Bunge, an ornamental and medicinal plant. Through quantitative trait locus (QTL) mapping across three environments, 33 QTLs associated with anthocyanidin content—a key pigment group influencing flower color—were identified, with two major QTLs located on linkage groups LG4 and LG5. Within these regions, two candidate genes were discovered: CHS1, encoding chalcone synthase 1, which likely promotes anthocyanidin biosynthesis, and TCP15, a transcription factor that may act as a negative regulator. Expression analyses showed that CHS1 expression correlates positively with flower color intensity, while TCP15 expression is inversely related, suggesting their opposing roles in anthocyanidin accumulation and flower pigmentation. These findings provide a genetic foundation for further functional studies and breeding efforts aimed at diversifying flower color in S. miltiorrhiza.