Genetic analysis of production characters in Lolium

Summary The genetical control of heading date and dry matter production in an F2 population of Lolium perenne are presented from analyses of triple-test-crosses and basic generations. The data is derived from spaced plant trials at sites in the United Kingdom (UK) and Italy in different years. Despite the wide initial cross between UK bred material and an Italian accession, there was no significant evidence for epistasis, while additive and dominance variation were generally present with partial to complete dominance for all traits. Linear regression onto the environmental means accounted for all the GxE variation for dry matter production in the establishment and aftermath cuts, but not for heading date or the hay cut. The b values measuring responsiveness to the environment were clearly heritable and showed partial dominance. Predictions of the likely performance of recombinant inbred lines and second cycle hybrids were sufficiently promising to support further investigation of these approaches to breeding in this crop.