水杉赤枯病病原形态及分子鉴定

Morphological and molecular identification of Metasequoia red blight

对上海、南京地区的水杉赤枯病(Metasequoia red blight)的发生情况进行了调查和分析,并采用形态学和分子生物学结合的方法对该病的病原菌进行了鉴定。结果表明:单行种植和单棵零星分布的水杉感病程度相对于已经郁闭成林的水杉要严重得多;用作行道树的水杉抗病能力较弱,发病情况相对于农田中的水杉较为严重;生长势弱的水杉植株容易发生赤枯病,这一现象在行道树中表现尤为明显。通过对水杉赤枯病病原菌分离培养、人工接种试验、分离菌形态学观察及分子生物学分子鉴定,水杉赤枯病的病原菌被鉴定为细极链格孢(Alternaria tenuissima)和异角状拟盘多毛孢(Pestalotiopsis heterocornis)。

The occurrence regularity of Metasequoia red blight disease in Shanghai and Nanjing were investigated and an- alysed. The pathogens of the disease were identified with morphological and molecular methods. Results showed： Meta- sequoia of single row or sporadic distribution was more sensitive than that with a higher canopy density. The resistance of Metasequoia that used as street tree was weak, and the disease was more serious than that planted in farm. The Metase- quoia with a poor growth potential was more likely to be infected, especially the ones used as street trees. By isolation and culture of diseased tissue, artificial inoculation test, morphological observation and molecular identification by ITS a- nalysis of the isolated strain, the pathogen of Metasequoia red blight was identified as Alternaria tenuissima and Pestaloti- opsis heterocornis.