Analysis on Combining Ability for Characters of Male Sterile Lines in Rapeseed (Brassica napus L.)

The male sterile line is very important in the hybrid breeding program of rapeseed. This study was conducted to evaluate the combining ability of many characters of male sterile lines in Brassica napus L. Ten recessive genetic male sterile (RGMS) lines were used as parents to produce 45 single cross hybrids by using a half diallel cross method. These 45 crosses and their 10 parents were evaluated at Guiyang during 2007–2008. The results showed that both general combining ability (GCA) and specific combiing ability (SCA) effects were important for all characters, but additive gene effects were more predominant than non-additive gene effects. Qianyou 8AB and You 2894AB gave respective highly significant GCA effects of 230.94 and 127.65 kg • hm−2 for seed yield. Lines You 2894AB, QH303-4AB, You 157AB and You 2341AB gave highly significant GCA effects for oil content of 0.99, 1.62, 1.20 and 1.53%, respectively. The crosses among lines Qianyou 3A×Qianyou 8B, Qianyou 8A×You 2894B, You 2894A×Qianyou 6B, Qianyou 8A×QH303-4B and Qianyou 8A× Qianyou 6B gave high SCA effects of 616.29, 398.71, 356.48, 394.24 and 303.79 kg hm−2 for seed yield, respectively. All these crosses also gave high seed yield indicating that these crosses could be used in the breeding program.