紫藤叶斑病病原鉴定

Identification of the leaf spot pathogen in Chinese wisteria in Anhui Province

通过采集安徽霍邱县和池州市园林植物紫藤感病的新鲜叶片,进行分离和纯化,获得病原纯培养,并对其进行形态和分子鉴定及致病性测定,明确了紫藤叶斑病的病原种类及其分类地位。结果表明,室内外接种和田间观察表现出相同的症状,从叶片组织上分离纯化得到2株分离株,形态观察结果表明均为链格孢属链格孢(Alternaria alternate)。利用真菌rD NA-ITS通用引物进行PCR扩增并测序和比对分析,结合形态学特征确定引起紫藤叶斑病的病菌均为链格孢菌Alternaria alternate(Fr.)Keissler。

Fresh leaves with disease spots were collected from Chinese wisteria （Wisteria sinensis）, a garden plant species, in Huoqiu County and Chizhou, Anhui Province. In order to classify the pathogenic species, the pathogen was isolated and purified, and further identified using morphological and molecular methods. The mor- phological observation of the conidia indicated that the pathogen might be Alternaria alternate （Fr.） Keissler. Moreover, the sequence was amplified using universal primer of rDNA-ITS of fungus, and the sequence analysis of its rDNA-ITS region showed that it was 100% similar to Alternaria alternate. Pathogenicity tests and confirm- ing Koch＇s postulates verifier the result.