贵州六盘水地区大白菜黑斑病病原菌鉴定及培养特性研究

Identification of Pathogen Causing Black Spot Disease on Chinese Cabbage in Liupanshui District of Guizhou and Studies on Its Cultural Characteristics

黑斑病是大白菜重要病害之一,常对大白菜田间生产造成严重损失。为明确引起贵州省六盘水地区大白菜黑斑病的病原菌种类,采用稀释涂布法从六盘水地区4个种植点大白菜黑斑病病样上分离到4个菌株。基于形态学和ITS、Alt-a1、tef-1多基因序列分析,4个菌株的鉴定结果均为芸薹链格孢Alternaria brassicae。生物学特性研究表明,该病原菌最适培养基为PDA,最适氮源为酵母浸粉和蛋白胨,最适碳源为葡萄糖;菌丝生长及孢子萌发最适温度均为25℃,菌丝生长最佳pH值为7;分生孢子致死温度为55℃下处理10 min。

Black spot disease is one of the important diseases for Chinese cabbage,often causing severe damage in field production.In order to identify the species of pathogen of black spot disease of Chinese cabbage grown in Liupanshui District of Guizhou Province,this study took 4 strains isolated from Chinese cabbage black spot disease samples in 4 cultivated sites of Liupanshui District by dilution coating method.Based on morphological characteristics and ITS,Alt-a1,tef-1 polygenic sequence analysis,4 strains were all identified as Alternaria brassicae.Results of biological characteristics study indicated that PDA was the optimal medium for this strain,and its optimal carbon sources were yeast extract power and peptone.Its optimal nitrogen source was glucose.The optimum temperature for mycelium growth and spore germination were 25℃.The best pH for mycelium growth was 7.The lethal temperature of spore was below 55℃treating with 10 min.