我国部分地区大豆疫霉群体遗传分析

Genetic structure analysis of Phytophthora sojae population from several provinces in China

为探究我国大豆疫霉菌的遗传多样性,使用13对简单重复序列标记(simple sequence repeats,SSR)引物对来自部分地区的79个大豆疫霉菌分离物进行了DNA指纹分析。13对SSR引物共扩增出33条条带,其中多态性条带比例为97.0%。SSR指纹聚类分析表明:当以相异距离0.79为阈值时,可将79个大豆疫霉菌分离物划分为13个遗传聚类组。多数大豆疫霉菌分离物之间遗传相似性较低,表明我国大豆疫霉在DNA水平上发生了显著的遗传变异,从而具有较丰富的遗传多样性。大豆疫霉菌DNA多态性特征与分离物地理来源之间存在一定相关性,说明不同地区的大豆疫霉菌群体与大豆栽培品种之间的互作很可能是引起大豆疫霉菌发生广泛遗传变异的主要原因。

The primary objective of this study was to explore genetic diversity among Chinese Phytophthora sojae isolates.The fingerprints of 79 P.sojae isolates from part of regions of China were determined using 13 simple sequence repeats（SSR）primers.A total of 33 reproducible SSR fragments were scored among 13 primers,of which 97.0% were polymorphic among the Chinese P.sojae population.The cluster analysis with the unweighted pair group method revealed that the 79 isolates of P.sojae were separated clearly into thirteen clusters（genotypes）in 0.79 dissimilarity distance.The genetic similarity among major of P.sojae isolates was low,indicating that there were abundant genetic diversities among Chinese P.sojae isolates as a result of remarkable genetic variations that occurred in DNA level.The analysis results in this study showed that there is certain correlation between P.sojae isolates genomic DNA polymorphisms and their originations,suggesting the interaction between P.sojae and soybean cultivars with genetical backgrounds may contribute to the wildly distributed genetical diversity among Chinese P.sojae strains.