油茶叶枯病菌的鉴定及生物学特性研究

摘要

The Camellia oleifera blight pathogen was identified as Pestalotiopsis microspora. In vitro culture showed that PDA medium was the best for the mycelial growth of pathogen. No conidium was produced when growing in crapek's medium. Conidia sporulated best on OMA medium. Temperature ranged from 20 to 30 ℃ and 25℃. were optimum for its mycelia growth and spore sporulation. Spores could not produced below 10 ℃ or over 30 ℃. pH ranged from 4 to 11 was optimum for its mycelia growth, while pH7 was optimum for conidium sporulation. The mycelia grew best on media with fructose as C source, and conidia sporulated best on media with D-Glucose as C-source. Peptone nitrate and KNO3 nitrate were the best nitrogen sources for mycelial growth while peptone nitrate was the best for conidium sporulation. Continuous light or 12 h light/12 h dark cycles were the best for mycelial growth and conidium production. The lethal temperature for conidium was 52 ℃, 10 min.%从海南五指山油茶园区采集到油茶叶枯病叶,进行病原菌分离鉴定并对其生物学特性进行研究.通过对其培养特性、形态特征的观察及rDNA的转录间隔区(ITS)序列测定,与Genbank中同源性较高的菌株进行序列比对,将该病原菌OC-12确定为小孢拟盘多毛孢(Pestalotiopsis microspora).生物学特性研究结果表明:OC-12菌丝在PDA培养基上生长最佳,在crapek培养基上不产孢,在燕麦培养基上最适合产孢.菌丝生长和分生孢子产生的适宜温度分别为20～30℃和25℃,适宜pH值为4～11.供试碳源中果糖较利于菌丝生长,D-葡萄糖较利于孢子产生；供试氮源中蛋白胨和硝酸钾较利于菌丝生长,且蛋白胨较利于孢子产生.分生孢子致死温度为52℃,10 min.