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选用16对毒性相关基因特异性引物对四川和重庆9个县(市)分离到的200个稻瘟病菌单孢菌株进行PCR扩增,并采用最长距离法进行聚类分析,结果显示各引物均能扩增出其目的条带,多态位点百分率(P)高达93.75%,扩增频率差异较大;200个菌株可归为70个不同的单元型,其中单元型SCH13为优势单元型;在0.86遗传相似水平上,200个菌株可划分为27个遗传宗谱,包括1个优势宗谱,3个亚优势宗谱,14个次要宗谱,9个小宗谱,层次丰富;在群体平均水平上,病菌群体具有丰富的遗传多样性(H=0.324 4,I=0.484 2),且群体间差异较大;9个种群在遗传距离为0.05水平上可分为4个类群,种群遗传谱系与地理区域分布呈一定相关性。同时,该地区的群体存在一定的遗传分化(HT=0.320 0),群体内多样性大于群体间多样性(Hs=0.179 6,Dst=0.140 4),总遗传变异的56.13%存在于群体内(Gst=0.438 7),群体间基因流动性较小(Nm=0.639 6)。本研究揭示了四川和重庆部分区域稻瘟病菌群体遗传结构、遗传多样性及其与地理分布之间的关系,为抗病育种和品种布局奠定了基础。
Sixteen pairs of Toxoplasma gondii-specific primers were used to amplify 200 M. grisea isolates isolated from 9 counties (cities) in Sichuan and Chongqing. Cluster analysis was performed using the longest distance method. The results showed that each primer The percentage of polymorphic loci (P) was as high as 93.75% and the frequency of amplification varied greatly. The 200 strains could be classified into 70 different haplotypes, of which the haplotype SCH13 was the dominant haplotype At genetic level of 0.86, 200 isolates could be divided into 27 genetic lineages, including 1 dominant lineage, 3 subdominant lineages, 14 minor lineages and 9 minor lineages, The average population level was rich in genetic diversity (H = 0.324 4, I = 0.484 2), and there were significant differences among populations. Nine populations were divided into four groups at a genetic distance of 0.05, Population genetic lineages and geographical distribution of a certain correlation. At the same time, there was a certain degree of genetic differentiation in the population (HT = 0.320 0). The intraspecific diversity was greater than the inter-population diversity (Hs = 0.179 6, Dst = 0.140 4) and 56.13% of the total genetic variation Gst = 0.438 7), and the gene mobility among populations was smaller (Nm = 0.639 6). This study revealed the genetic structure, genetic diversity and geographical distribution of Magnaporthe grisea in rice in some areas of Sichuan and Chongqing, which laid the foundation for disease-resistant breeding and variety distribution.