龙柏叶枯病的发生特点及其病原菌分离鉴定

Isolation and Identification of Leaf Blight of Sabina chinensis cv. Kaizuka

龙柏叶枯病是近年来中国园林植物上出现的新病害，以小龙柏受害最为严重。本研究采用田间实地调查、室外试验分析研究了龙柏叶枯病的症状及发生特点，并结合形态学观察及ITS序列分析对分离纯化的龙柏叶枯病的病原菌进行了鉴定。结果表明，龙柏叶枯病受害植株鳞叶小枝从上向下迅速干枯为其典型症状，春季冷凉、多雨的气候条件及强度修剪是该病发生的主要原因；形态学观察及ITS序列分析表明龙柏叶枯病菌的无性时期为链格孢，菌丝为有隔菌丝，分生孢子黄褐色，大小20．5～32．5μm×6．5—10μm，有纵横隔膜且分隔处明显缢缩，有性时期属于子囊菌。

Leaf blight of Sabina chinensis cv. Kaizuka is a kind of new disease on landscape plants and its seedlings are vulnerable to the infection. The symptom and characteristics of the occurrence of the leaf blight of S. chinensis cv. Kaizuka were studied by field experiments and surveys, and the isolated pathogen was identified based on the morphological characters and ITS sequence analysis. The results showed that the scale leaves withered from top to bottom was the typical symptom of the diseased plants, and the cool and rainy weather in spring and frequent pruning were the main causes of the leaf blight of S. chinensis cv. Kaizuka. By morphological observation and ITS sequence analysis, the imperfect stage of the pathogen of Leaf blight of S. chinensis cv. Kaizuka was identified as Aternaria alternate. The mycelium were isolated one with brown conidia of 20. 5 -32.5μm×6. 5 - 10μm, crossbar diaphragm , and its perfect stage was Ascomycete.