Identification of QTL Associated With Luteolin Content in Peanut (Arachis hypogaea L.) Shells

Investigating the inheritance and genetic variation of luteolin content in peanut shells is pivotal for developing improved cultivars with high luteolin content. In this study, we developed a genetic map spanning 976.8 cM using 115 highly advanced recombinant inbred lines (RILs) and the Axiom_Arachis array containing 58K single-nucleotide polymorphisms (SNPs). Quantitative trait locus (QTL) analysis was then performed using phenotype data from 2-year field trials. From these analyses, we identified three significant QTLs with 4.1%–11.7% phenotypic variation explained (PVE) for luteolin content in peanut shells. We further identified five candidate genes with putative functions suggesting possible involvement in plant flavonoid and terpenoid biosynthetic pathways in peanut luteolin biosynthesis. Additionally, two new peanut inbreeding lines with high luteolin and oleic acid levels were selected and are expected to be used as multifunctional genomic backgrounds for future breeding and research programs. The information on the QTL regions and candidate genes from the present study could be very useful for developing new peanut cultivars with high luteolin content and for identifying the genetic/genomic determinants of luteolin content in peanut shells.