QTL mapping and gene discovery in perennial ryegrass (Lolium perenne L.)

Winter hardiness is a complex quantitative trait that limits geographic distribution of ryegrass. Improving winter hardiness is an important breeding goal in ryegrass breeding programs. An understanding of the genetic basis for the component traits of winter hardiness would allow more efficient selection. A three-generation interspecific population of an annual x perennial ryegrass consisting of 152 progenies was used to map quantitative trait loci (QTL) that control winter hardiness related traits including fall growth (FG), freezing tolerance (FT), and winter survival (WS) over two years. A total of twenty-six QTLs were identified for the three traits from both the female parental (MFA) and the male parental maps (MFB), of which seven were for FG, six for FT, and thirteen for WS. The proportion of phenotypic variation