Patterns of Heterosis in Three Distinct Inbred Populations of Spring Canola

摘要

Allelic diversity of the allied species of Brassica napus L. as well as of the winter form of this species has been demonstrated to be related with increasing productivity of hybrid spring B. napus cultivars. To compare potential value of the different gene pools of Brassica species three spring B. napus inbred populations were developed by use of a B. oleracea L. line, a spring B. napus breeding line, and a winter B. napus cultivar crossed to a spring B. napus a€?Hi-Qa€?; and test hybrids of these inbred lines were produced by crossing with Hi-Q as the common tester. Mid-parent heterosis (MPH) showed a negative correlation with seed yield of the inbred lines in all three populations; however, a positive correlation existed between seed yield of the inbred lines and heterosis over Hi-Q (HiQH) (or, inbred vs. hybrid yield). On average, the level of MPH in hybrid of the inbred lines derived from B. napus ?— B. oleracea cross was twice greater than the level of heterosis found for the inbred lines derived from spring ?— spring or winter ?— spring B. napus crosses. The inbred population derived from winter ?— spring cross gave highest seed yield, and this population also gave highest HiQH. The results suggested that B. oleracea and winter canola could be used in spring B. napus canola breeding for accumulating additive and non-additive effect genes for increased seed yield in hybrid cultivars.