稻瘟病菌群体的分子遗传学研究——广东地区特异性宗谱菌株的分子指纹和致病型分析

Molecular Genetic Studies on the Rice Blast Fungus Population DNA fingerprinting and pathotype analyses of the isolates selected from the region-specific lineages of Guangdong Province, China

为了解稻瘟病菌遗传宗谱与致病型的对应关系 ,构建适于广东省稻瘟病菌群体的鉴别菌株。根据以前试验结果 ,选择 2 7个广东省地区特异性宗谱菌株 ,进行了基于SRAP标记的第二次分子指纹分析 ,以及基于中国、日本和CO39近等基因系 3套鉴别品种的致病型分析。当遗传相似系数为 0 .85时 ,这些菌株被划分为 2 3个遗传宗谱 ,说明这些菌株具有丰富的遗传多样性 ,但其遗传发育关系与第一次分子指纹分析的结果有比较大的差异。这些菌株经中国、日本和CO39近等基因系 3套鉴别品种测试 ,划分为 11、2 2和 16个致病型或小种 ,其中与遗传宗谱存在对应关系的致病型数分别为 2、10和 8个 ,推断这些菌株具有丰富的致病型多样性。从遗传宗谱和致病型的多样性等因素考虑 。

According to the results of the previous experiment, 27 isolates derived from the region-specific lineages of Guangdong Province (GD), were selected to analyse the relationship between pathotype and lineage using another 10 pairs of SRAP (sequence-related amplified polymorphism) primers. The phylogenetic relationships of these isolates were certainly different from those characterized by the first 10 pairs of SRAP primers in the previous study. On the other hand, pathotypes of 27 isolates were assessed with three sets of differential cultivars from China, Japan and the International Rice Research Institute (IRRI). As to the Chinese differentials, 11 pathotypes were determined, and only two pathotypes were corresponding to their lineages. As to the Japanese differentials, 22 pathotypes were determinated, and 10 pathotypes were specific to their lineages. And to the IRRI's differentials, 16 pathotypes were determinated, and 8 pathotypes were responsible to their lineages. The results from the research suggested that these isolates should be recommended as the candidate differential isolates specific to GD, because they had high diversities of genetics as well as pathogenesis. The relationship between genetic lineage and pathotype is also discussed.