我国长江以南地区水稻白叶枯病原菌遗传多样性分析

Genetic Diversity of Pathogen Xanthomonas oryzae pv. oryzae from Southern Regions of Yangtze River in China

用 IS- PCR和 rep- PCR法结合传统病理学分析了 12 8个主要采自我国华中、华南和西南地区的水稻白叶枯病菌(Xanthomonas oryzaepv. oryzae)的群体遗传多样性。用 4个专化引物 J3、ERIC、REP和 BOX对 114个菌系基因组 DNA进行 PCR扩增反应 ,4个引物分别呈现 2 0、12、6和 5种谱型 ,遗传多样性值分别为 0 .82、0 .49、0 .35和 0 .30。以彼此间带位相似率达 70 %为界 ,用 UPGMA聚类分析法 ,可将 114个病原菌分为 6簇 (J3)和 5簇 (ERIC)。引物 J3的簇 1中包括 0～ 、 7个病原型 ,ERIC引物的簇 1中包括 0～ 和新型 9个病原型。将 12 8个病原菌在我国 5个鉴别品种上测定以进行病原型分群 ,参试菌系多数属于 型、 型和 0型 。

IS PCR and rep PCR were used to analyze the genetic diversity in a population of 128 strains of Xanthomonas oryzae pv. oryzae collected mostly from Center, South and Southwest China. Genomic DNA from 114 strains was amplified with four specific primers, J3, ERIC, REP and BOX by PCR and revealed 20, 12, 6 and 5 haplotypes, respectively. The genetic diversities of the population of strains tested were 0.82 (for J3), 0.49 (for ERIC), 0.35 (for REP) and 0.30 (for BOX), respectively. Dendrograms were generated from the data sets obtained by using UPGMA analysis. All strains tested were similar to each other at a level of 70% similarity, six and five clusters were grouped using primers J3 and ERIC, respectively. The strains classified into Chinese pathotypes 0-Ⅴ and Ⅶ were grouped in Cluster 1 for primer J3; Strains from pathotypes 0-Ⅶ, and a new pathotype were grouped in Cluster 1 for primer ERIC. One hundred and twenty eight strains were classified into different pathotypes by assessing on the five differential varieties. Most of strains were classified into pathotypes Ⅳ, Ⅱ and 0. A new pathotype was identified based on its reaction pattern different from all the seven Chinese pathotype.