稻瘟病菌杂交后代致病性遗传分析

为明确稻瘟病菌杂交后代对水稻致病性的遗传规律,以亲本菌株HLJ6122和KA3杂交产生的后代群体为试验材料,将其接种于14个单基因系抗性水稻品种,对杂交后代进行毒性差异分析。结果表明,64个杂交后代菌株呈现显著的毒性分离,共出现53种毒性类型,无毒性/毒性分别表现为1∶1、1∶3、3∶1、15∶1。菌株KA3分别对IRBLi-F5、IRBLta-K1、IRBL12-M、IRBLta2-Pi持有1个无毒基因;对品种IRBLa-A、IRBLzt-T、IRBL7-W、IRBLkm-Ts、IRBL20-IR24持有2个无毒基因。64个后代菌株对品种IRBLk-Ka、IRBLz-Fu、IRBL19-M、IRBLb-B、IRBLkp-K60无毒性/毒性也符合1∶3,但2个亲本菌株HLJ6122和KA3对供试水稻品种致病性相同,因此难以判断无毒基因的来源。

Genetic Analysis of Pathogenicity of Sexual Progeny of Magnaporthe oryzae

To clarify the difference of avirulence/virulence in sexual progeny of Magnaporthe oryzae. The progeny population produced by the cross of the parental isolates HLJ6122 and KA3 were used as the test material. the virulence of the sexual progeny was analyzed by inoculating it into 14 single line resistant rice varieties. The results suggested that 64 progeny isolates showed significant virulence segregation and 53 virulence types appeared, the segregation ratios of avirulence/virulence were 1:1, 1:3, 3:1 and 15:1 on different rice varieties, respectively. Avirulence and virulence on rice varieties IRBLi-F5, IRBLta-K1, IRBL12-M, IRBLta2-Pi were controlled by a single gene and by 2 genes on varieties IRBLa-A, IRBLzt-T, IRBL7-W, IRBLkm-Ts, IRBL20-IR24. The segregation of avirulence/ virulence on IRBLk-Ka, IRBLz-Fu, IRBL19-M, IRBLb-B and IRBLkp-K60 in the 64 progeny isolates fit 1:3 ratio, but the avirulence and virulence of parental isolates to varieties was the same, it is therefore, difficult to judge the source of avirulence genes. The above results are of great significance to the localization and cloning of avirulence genes of Magnaporthe oryzae.