Genetic diversity of phytophthora infestans of potato in yunnan based on two microsatellite （SSR） markers

chinois. 【目的】检测不同马铃薯产区晚疫病菌基因型的特征,揭示马铃薯晚疫病菌群体的进化潜能和演替。【方法】用已开发出来的微卫星标记（SSR）对云南省23个马铃薯产区的晚疫病菌群体的遗传结构进行研究。【结果】在两个SSR位点Pi4B和Pi4G上共检测到8个等位基因,占优势的等位基因是218和161,基因频率分别为84.02%、32.52%。在分析的235个云南晚疫病菌菌株中,检测到18个不同的SSR基因型,其中8个新的SSR基因型谱系H-03、H-04、H-05、H-06、H-07、I-01、J-01和K-01被首次检测到;SSR基因型D-03、D-05、H-01和H-05是云南马铃薯晚疫病菌群体的优势谱系,在云南的群体中所占的比例分别为20.85%、22.98%、15.32%和19.57%,分布于云南的大部分马铃薯产区。【结论】云南马铃薯晚疫病菌群体遗传多样性在地理分布上差异明显,滇中多季作种植区晚疫病菌群体显示了较高的遗传多样性,滇南冬播作一季种植区群体结构单一。有证据表明中国云南晚疫病菌群体与其它国家20世纪80年代后出现的晚疫病菌群体在遗传上存在关联。

anglais. [ Objective] This study was performed to detect the genotypic characteristics ofPhytophthora infestans populations and reveal the evolutionary potential and replacement of pathogen. [Method] The population genetic structure of P. infestans of potato collected from twenty three potato regions in Yunnan was analyzed based on the developed microsatellite markers （SSR）. [Result] Eight alleles were detected on two SSR loci, Pi4B and Pi4G, from Yunnan populations. The 218 and 161 alleles were predominant SSR ones among eight alleles and the gene frequency was 84.02% and 32.52%, respectively. Total eighteen different SSR genotypes were determined among 235 isolates and eight new SSR genotypic lineages, H-03, H-04, H-05, H-06, H-07, ]-01, J-01 and K-01, were firstly detected worldwide. The SSR genotypes, D-03, D-05, H-01 and H-05, were main lineages among populations, which spread out most potato production regions, having genotypic ratio 20.85%, 22.98%, 15.32% and 19.57%. [ Conclusion ] The geographical distribution of genotypic diversity of P infestans populations is different significantly in Yurman. The genetic diversity of P infestans populations in middle multiple cropping zones is high, however, that in south winter planting zones is low. The strong genetic evidence shows that the populations of P. infestans in Yunnan are related to those of other countries occurred after the second worldwide migration of P infestans.