抗根肿病甘蓝型油菜新种质的创制及抗性评价

Establishment and Resistance Evaluation of New Clubroot-resistant Germplasm of Brassica napus

【目的】通过根肿病高抗白菜品种"康根51"与甘蓝型油菜种质进行杂交,创制获得对云南特定根肿病生理小种具有抗性的种质,为根肿病抗性育种奠定基础。【方法】采用染色体数目和PCR扩增对亲本和杂交后代进行分析,并采用田间抗性鉴定和室内人工接种鉴定相结合的方法进行抗性评价。【结果】染色体数目分析发现,"康根51"的染色体数目为20条,油菜10159染色体数目为38条,杂交F_1代材料染色体数目为29条,与预期结果相符。随着世代的增加,染色体数目逐渐趋于正常且自交结实正常。PCR扩增结果显示杂交后代具有双亲的互补带型,表明创制的种质为甘、白杂交后代种质。对不同世代的663份自交单株进行田间根肿病抗性初筛,29份材料发病率较低;以楚雄东瓜镇油菜发病根瘤上分离的休眠孢子为病原对田间初筛的种质进行室内抗性鉴定。R150和R322表现为高抗,发病率分别为6.7%和13.3%,病情指数分别为5.83和7.50;R072、R087等19份材料表现为抗病,发病率在13.3%～36.7%,病情指数在10.83～25.80,其余8份表现为感病或高感。相关性分析表明,油菜根肿病的病情指数与发病率呈显著正相关。【结论】获得对云南特定根肿病生理小种表现抗性的甘蓝型油菜新种质2份,可用于油菜根肿病抗病育种。

【Objective】To obtain clubroot-resistant Brassica napus germplasm in Yunnan and lay a foundation for resistance breeding,clubroot-resistant Chinese cabbage variety‘CR51’was crossed with clubroot-susceptible Brassica napus.【Method】Chromosome numbers and PCR amplification were conducted to analyze the parents and filial generations,and the method of field resistance identification and artificial inoculation was used to evaluate the resistance of parents and progenies.【Result】Chromosome numbers analysis showed that the number of‘CR51’was 20,rapeseed 10159 was 38 and the number of F1 was 29,consistent with the expected results.With the increasing of generation,the number of chromosome and self-fruitfulness tended to be normal.PCR amplification results showed that the F2 hybrid possessed the complementary bands of parents,which indicated that they were hybrids of Chinese cabbage and rapeseed.29 offspring at different generations with low disease incidence were selected by field clubroot resistance identification.Clubroot pathogen obtained from Donggua Town of Chuxiong was used to artificial inoculation,which showed that R150 and R322 were highly resistant to clubroot,the disease incidence was 6.7%and 13.3%,the disease index was 5.83 and 7.50,respectively.19 germplasm such as R072,R087 were resistant to clubroot,and the disease incidence was between 13.3%and 36.7%and the disease index was between 10.83 and 25.80.The rest 8 germplasm were susceptible or highly susceptible to clubroot.Correlation analysis showed that there was a significant positive correlation between the disease index and incidence of clubroot in brassica napus.【Conclusion】Two new germplasm of Brassica napus highly resistant to certain physiological race in Yunnan were obtained via interbreeding which could be used in rapeseed clubroot-resistance breeding.