核桃基腐病的病原鉴定

Pathogen Identification of Walnut Stalk Rot Disease

从新疆阿克苏地区核桃园发病的核桃树上采集的病样经分离、纯化得到2种菌。经田间人工接种致病性测定,明确了引起核桃基腐病的病原菌。根据形态特征和培养特性初步鉴定核桃基腐病的病原菌为寡雄腐霉。采用真菌通用引物对分离的病原菌进行PCR扩增,核糖体DNA内转录间隔区测序,并将测序结果在GenBank中进行同源性比对分析,分子鉴定与形态鉴定结果一致。寡雄腐霉作为核桃基腐病病原菌系首次报道。

A new canker disease had taken place on walnut（Juglans nigra） in Xinjiang.In resent years,it has caused severe damage to the walnut product.In this paper samples were collected from diseased walnut in walnut gardens and 2 isolates were obtained.The isolates were inoculated with both wound and healthy inoculation methods.Re-isolation from lesions formed by the inoculation was the same as the inoculatied isolate,demonstrating that the isolate was a pathogenic strain of Pythium oligandrum based on its morphology.The sequences of the isolates Pythium oligandrum were amplified by PCR technique with universal primers of fungi,and the sequences were further compared with that in GenBank.The molecular identification confirmed the results from morphology identification.This is the first report that Pythium oligandrum is the pathogen of walnut black water disease in China.