新品种绿珍8072和白香占的抗白叶枯病遗传分析及其基因检测

Genetic Analysis and Gene Detection of New Varieties Lvzhen8072 and Baixiangzhan with Bacterial Blight Resistanc

白叶枯病(Xanthomonas oryzae pv.oryzae,Xoo)是水稻最严重的细菌性病害,抗病品种的培育利用是控制该病最经济有效的措施。本研究对新选育的抗白叶枯病品种绿珍8072和白香占抗性基因鉴定及遗传分析,以供生产应用参考。以绿珍8072和感病籼稻品种金刚30杂交,对亲本、F1和F2代接种广东白叶枯病强致病性菌系V型菌GD6027进行表型抗性鉴定,并利用与Xa7紧密连锁的微卫星标记对亲本和F2代个体进行了多态性和连锁分析,确定绿珍8072含有Xa7等位抗性基因并独立遗传;用同样的方法鉴定了白香占的抗性基因及其遗传方式,结果表明,白香占抗白叶枯病基因与xa5基因相关,但其F2代抗感病表现型和基因型分离比,不符合孟德尔隐性单基因遗传抗感(1:3)的分离比定律,存在偏分离现象。

Bacterial blight （Xanthomonas oryzae pv. oryzae, Xoo） is one of the most serious bacterial diseases for rice all over the world. Breeding resistant varieties is one of the most economical and effective measures to control rice bacterial blight. In this research, gene identification and genetic analysis were made on the newly cultivated varieties Lvzhen8072 and Baixiangzhan in order to provide references for farming. First LvzhenS072 was hybridized with indica rice cultivar Jingang30 （highly susceptible to Xoo strains）. Then the parental generation, LuzhenS072 and Jingang30, and their F, and F2 individuals, were inoculated highly pathogenic V-type strains of bacterial blight from Guangdong Province, GD6027, to identify resistant phenotypes. And Xa7-1inked micro- satellite markers were used to detect the parents＇ polymorphism and to confirm the linkage between Xa7 and its makers among F2 individuals. The result shows that Lvzhen8072 harbors the resistance gene allelic to Xa7 which is independently inherited. In the same way, the bacterial blight resistance gene of Baixiangzhan and its hereditary pattern were identified. The result shows that it is related with xa5 gene. But the segregation radio of F2 resistant and susceptible individuals＇ phenotype and genotype segregation are different from segregation radio （1：3） based on Mendelian laws of inheritance. Segregation distortion has been present.