橡胶树毛色二孢叶斑病病原菌的鉴定及其生物学特性研究

Identification and Biological Characteristics of the Pathogen Causing Lasiodiplodia Leaf Spot of Robber Tree

近期在海南省三亚市的橡胶树种植区发现一种新的橡胶树叶斑病,利用组织分离法和单孢分离法获得纯化菌株HNSY003。通过形态学特征观察、rDNA-ITS和EF1-α序列分析及柯赫氏法则验证,确定该病原菌为假可可毛色二孢(Lasiodiplodia pseudotheobromae)。这是假可可毛二孢所致橡胶树叶斑病的首次发现。生物学特性测定结果表明,病菌最适生长条件为:温度32℃,pH 5,碳源为D-果糖,氮源为酵母浸膏。不同光照条件对菌丝生长影响不显著。

A new leaf spot disease of rubber tree was found in Sanya, Hainan. The pathogen strain HNSY003 was isolated and purified by methods of tissue isolation and single spore isolation. The pathogen was identified as Lasiodiplodia pseudotheobromae by morphological observation, sequence analyses of rDNA-ITS and EF1-α, and its pathogenicity was confirmed by Koch’s postulate. The fungal species is reported the first time as the pathogen of robber tree leaf spot. The results of biological characteristics test showed that the optimum conditions for the pathogen growth were as follows: temperature 32 ℃, pH 5, D-fructose as the carbon source, yeast extract as the nitrogen source. Different light conditions had little effect on the growth rate of the pathogen hypha.