中文摘要：

为明确辽宁地区葡萄霜霉病菌的遗传变异规律，对采自辽宁省不同地区的21株葡萄霜霉病菌提取DNA，采用特异性引物进行rDNA-ITS序列扩增与测定，并利用Clustalx1.83及MEGA4.0软件进行聚类分析，分析其遗传多样性。试验结果表明：21株葡萄霜霉病菌的ITS序列长度为1306～1781bp，GC含量为34.16%～36.09%；菌株遗传距离为0～0.069；以遗传距离0.01划分为2个类群，以遗传距离0.005划分为3个亚群。采自沈阳的SYK菌株和采自朝阳的CYE菌株遗传距离为0；采自大连的2个菌株分别属于类群玉的2个亚群，遗传距离为0.016。采自沈阳的6株菌株分别属于2个类群，聚类较分散；采自朝阳的6个菌株分别属于2个类群，聚类较分散；采自辽阳的2个菌株分别属于2个类群，亲缘关系较远。所测得的21个菌株ITS序列存在一定差异，辽宁省不同地区的葡萄霜霉病菌遗传差异与地域性未见明显的相关性，区域性特征不明显。

英文摘要：

The Plasmopara viticola is an important disease to the grape. In order to study the variation pattern of Plasmopara viticola, 21 strains were collected from different areas in Liaoning Provinces. Using specific primers to acquire ITS sequences of 21 strains and sequenced. The clustering analyses were carried out by Clustalx1.83 and MEGA4.0 software. The phylogenetic tree was constructed about the sequence and study the genetic diversity. The results showed that the sequences of ITS were 1306~1781bp, and GC contents were 34.16%-36.09%. The genetic distance among all strains was 0~0.069. By genetic distance 0.01,21 strains belonging to two groups, with 0.005 is divided into three subsets. The genetic distances among SYK from Shenyang and CYE from Chaoyang is 0. Two strains from Dalian were clustered into two group, the relationship was far; six strains from Chaoyang were clustered into two group, the relationship was far. Two strains from Liaoyang were clustered into two group, the relationship was further. There is a certain degree of genetic differentiation between strains. To the strains of Plasmopara viticola, there was no significant relationship between genetic differences and regions in different areas.