Identification of QTL for Plant Architecture and Flowering Performance Traits in a Multi-Environment Evaluation of a Petunia axillaris × P. exserta Recombinant Inbred Line Population

Field performance of herbaceous annual plants is largely determined by plant architecture and flowering performance. A Petunia axillaris × P. exserta F7 recombinant inbred line population was grown in four field environments across the United States, phenotyped for seven habit flowering-related traits: height (Height), maximum (MaxWid) minimum (MinWid) width, vigor, compactness (Comp), canopy coverage (Flow) flower color retention (ColorRet). Robust QTL (rQTL; detected two or more environments) were identified all traits except width distributed five chromosomes. The largest effect rQTL explained up to 23.8, 19.7, 16.7, 16, 25.7, 36.9% observed phenotypic variation Flow, Vigor, Comp, ColorRet, Height MaxWid, respectively. Height, MaxWid colocalized on Chr 2, indicating this region could be particularly useful mining candidate genes underlying important petunia.