QTL mapping reveals a wild-derived segment controlling plant architecture in peanut (Arachis hypogaea L.) using a cultivar-wild hybrid population

BACKGROUND: Plant architecture is a key agronomic trait of peanut (Arachis hypogaea L.), which is closely associated with yield, stress resistance, and suitability for mechanical harvesting. However, research on the genetics and gene mining of peanut plant architecture remains relatively limited, thereby hindering the genetic improvement of peanut plant architecture. RESULTS: Most cultivated peanut varieties exhibit an erect or semi-prostrate growth habit, whereas wild peanut species predominantly display a trailing growth habit. In the present study, a recombinant inbred line (RIL) population, designated as the TI population was developed by crossing the female parent Tifrunner with the male parent IpaDur, a synthetic amphidiploid derived from cross of Arachis ipaënsis × Arachis duranensis. Traits related to plant architecture, including lateral branch angle (LBA), lateral branch length (LBL), main stem height (MSH), main stem thickness (MST), lateral branch thickness (LBT), internode length (IL), number of branches (NBS), and biomass (BIO), were evaluated across three environments. Based on a high-density genetic linkage map, 20 QTLs associated with these traits were identified, which explained 6.04%-18.68% of the phenotypic variance (PVE). A locus controlling LBA, LBL, and MST was mapped to an overlapping interval (122.57-137.18 Mb) on chromosome 14. Phenotypic effect analysis revealed that this wild species-derived segment is crucial for controlling the typical morphogenesis of wild-type peanut species. In addition, we identified a set of genotypes derived from cultivated-wild hybrid population, which exhibited the convergence of one or more favorable agronomical traits. CONCLUSIONS: Using a cultivar-wild hybrid population, 20 QTLs for plant architecture were identified in peanut. A wild-derived genomic segment was found to control typical wild-type morphogenesis. Novel germplasm pyramiding multiple agronomic favorable traits were selected. This study provides key theoretical insights and valuable resources for utilizing wild species in peanut improvement.