"Petunia (Petunia × hybrida) has ranked among the top three bedding plants sold in the United States since 1994 and was the top seller in 2013-2015. Understanding the genetics underlying traits related to flowering capacity will be useful to improve commercially available cultivars by decreasing flowering time and improving crop quality. Quantitative trait loci (QTL) mapping can facilitate understanding of the genetic control of flower production and development of marker-assisted breeding strategies to improve breeding efficiencies. In this study, an F7 P. axillaris × P. exserta recombinant inbred line population was phenotyped for several crop timing and quality related traits at three greenhouse temperature regimes and at four field locations. Total flower bud and branch number were positively correlated under two of the three greenhouse temperatures. Flowering performance was positively correlated with vigor and plant height at all field locations. All of these traits exhibited transgressive segregation in the population, indicating that they are under polygenic control, and have high broad-sense heritabilities, collectively suggesting that this population should be useful for identification of QTL associated with these traits. A total of 68 and 79 QTL for five greenhouse and seven field traits were identified using composite interval mapping. Thirty of these QTL were detected either at multiple temperatures, years, or locations suggesting that they are robust and useful for marker development. The identification and characterization of QTL underlying flower component traits in different environments provides new insight into the genetic and environmental control of flowering-related traits in petunia."--Page ii.
Read
