Combining ability of the new CMS-lines of winter rapeseed (Brassica napus L.) bred at VNIIMK

Combining ability (CA) of lines is one of the main criteria of estimation of the parental components of hybrids. There are existed the different crossing schemes for estimation of a combining ability. A method of top-cross is successfully used in a breeding practice. This method was used for estimation of a range of new CMS-lines of winter rapeseed perspective in breeding of simple interline hybrids. In our research we used six sterile lines on a base of CMS Ogura and six lines-restorers of fertility (testers). We obtained 36 test-hybrids for estimation of a combining ability of the lines. Positive combination of effects of the general combining ability (GCA) and variances of the specific combining ability (SCA), stable manifested in two years, we observed in two maternal lines 39712 and 40059. Hybrids with these lines had the higher average seed yield in two years of the research. These lines can be recommended for development of practically important hybrids of winter rapeseed. It is considered the testers possessing high GCA are promising for estimation of lines CA. in our research, two lines ORK 9 and ORK 21 demonstrated the high average seed yield of test-hybrids in two years of the research and can be recommended for usage as testers.