Analysis of combining ability and heterosis in winter oilseed rape Brassica napus L.

Most rapeseed breeding programs worldwide, have or are switching to hybrid varieties. Therefore, breeders need to obtain more information on the combining ability of inbred lines for hybrid performance across a wide range of environments. With the availability of the 'Ogura' CMS, it is possible to produce large quantities of test cross seeds to conduct multi-location yield trials of 'B. napus' hybrids. In this study nine female [male sterile] and four male [restorer] winter ' B. napus' inbreds were mated in a full North Carolina Design II mating scheme for the production of 36 fully restored F1 hybrids. Hybrids were planted in a total of seven locations in Canada, Germany and France to analyze for general combining ability (GCA) and obtain insight on the specific combining ability (SCA) for grain yield, quality and other important agronomic traits. In a second experiment, hybrids, together with the thirteen parental lines, were planted in two locations in Canada and Germany to estimate the level of heterosis for quality and agronomic traits. (Abstract shortened by UMI.)