Genetic improvement of clubroot resistance for the elite temperature-sensitive pol CMS line 616A in Brassica napus
To improve rapeseed resistance to clubroot,Huashuang 5R and Huayouza 62R(carrying PbBa8.1 locus and CRb locus,respectively)were used as donor parents for transferring the resistant genes into the elite tem-perature-sensitive pol CMS line 616A,by combining with successive backcross and marker-assisted selection.By the process,three improved temperature-sensitive pol CMS lines 616APbBa8.1,616ACRb and 616APbBa8.1+CRb were ob-tained,with genetic background recovery rates of 95.45%,94.80%and 92.58%,respectively.Subsequently,three clubroot resistant new hybrids Shengguang 128CRPbBa8.1,Shengguang 128CRCRb and Shengguang 128CRPbBa8.1+CRb were derived from these three improved lines and 621R(the male parent of Shengguang 128).Clubroot resistance of the improved lines and the hybrids was identified by using race 4,the dominant physiological race in China.Results showed that 616ACRb,616APbBa8.1+CRb and their hybrids(Shengguang 128CRCRb and Shengguang 128CRPbBa8.1+CRb)had im-munity to race 4.The improved line 616APbBa8.1 and the hybrid Shengguang 128CRPbBa8.1 were resistant to race 4;how-ever,their resistance levels were lower than those of CRb-containing lines and hybrids.Evaluation of agronomic traits showed that no significant differences were observed between the improved lines and 616A,neither between the improved hybrids and Shengguang 128.The traits included plant height,number of the branch,silique length,seeds per silique and thousand seeds weight.Therefore,it is possible to use the three improved lines for breeding rapeseed hybrids with clubroot resistance.
万方数据
维普
