苏辽粳稻区稻瘟病菌群体多样性比较

Population diversity of Magnaporthe oryzae of Jiangsu and Liaoning japonica rice area

采用四套鉴别品种对苏辽稻瘟菌进行鉴定,结果表明:257株菌被中国鉴别品种分为7群23个小种,其中苏辽菌株分别为5群12个小种、7群21个小种,江苏优势小种ZG1占其菌株数的52.92%;辽宁优势小种ZG1、ZC15占其菌株数的30.84%、19.63%。苏辽菌株分别含37、46个日本小种,江苏优势小种011、011.2、000占其菌株数的25.33%、14.67%、12.67%,辽宁优势小种011.2占其菌株数的28.97%;LTH近等基因系将苏、辽菌株划分为27、23个反应型。利用Pot2-rep-PCR技术进行遗传多样性分析,在75%相似水平上可将参试菌株划分为13个系谱,江苏12个系谱中优势系谱L11、L12、L4分别占其菌株数的22.67%、16.67%、17.33%,辽宁6个系谱中优势系谱L12占其菌株数的55.14%。苏辽相比,辽宁菌株毒力普遍强于江苏,两地稻瘟菌株的毒性多样性与遗传多样性的丰富度相反。综合分析显示,苏辽两地稻瘟菌是两个在致病型和遗传结构上相近而又异质性明显的不同群体。

Based on Chinese race differentials varieties, 257 Magnaporthe oryzae strains that isolated from Jiangsu and Liaoning Province were identified and categorized into 23 physiological races in 7 groups, in which Jiangsu isolates had 12 physiological races in 5 groups and Liaoning isolates had 21 physiological races in 7 groups. The frequency of dominant races ZG1 and ZC15 were 30.84% and 19.63% in Liaoning population; While it was 52.92% for Jiangsu dominant race ZG1. The Tsunematru mono-resistance gene lines from Japan differentiated Jiangsu and Liaoning strains into 37, 46 races respectively. In Jiangsu population the frequencies of dominant races 011, 011.2 and 000 were 25.33%, 14.67% and 12.67%, respectively; While it was 28.97% for Liaoning dominant race 011.2. Based on LTH-NILs Jiangsu and Liaoning strains can be categorized into 27 and 23 pathogenic types, respectively. Evaluation by Pot2-rep-PCR and setting the similarity at 75%, the genetic diversity of the tested strains can be categorized into 13 lineages, among which there were 12 in Jiangsu and 6 in Liaoning. The frequencies of dominant lineages Lll, L12 and L4 in Jiangsu were 22.67%, 16.67%, 17.33%, respectively; While it was 55.14% for Liaoning dominant lineage L12. In comparison to Jiangsu, the virulence of Liaoning strains was higher and the virulence diversity showed the opposite trend to the genetic diversity. Taken together, isolates from Jiangsu and Liaoning were similar in both pathogenicity and genetic structure but were significantly different in heterogeneity.