HETEROSIS IN SUMMER RAPE (Brassica napus L.)

The degree of heterosis for seed yield in F1 hybrids of summer rape (Brassica napus L.) was examined in replicated yield trials during 2 yr (1980 and 1981) using intervarietal hybrids produced by manual crossing. The seed yields from the F1 hybrids of crosses between Marnoo and Regent, and Karat and Regent exceeded those of Regent by 38 and 43%, respectively. With the possible exception of maturity, which was 1 day later than Regent, the agronomic and quality characteristics of these hybrids appeared to be within the ranges acceptable in commercial rapeseed cultivars. However, the successful development of hybrid rapeseed cultivars still depends upon the development of a suitable cytoplasmic, genetic or chemical (male gametocide) pollination control system.Key words: Brassica napus L., canola, intervarietal hybrids