苜蓿毁灭刺盘孢菌的主要生物学特性

Major biological characteristics of Colletotrichum destructivum causing anthracnose of alfalfa

苜蓿炭疽病是各苜蓿种植区分布较广的毁灭性病害。毁灭刺盘孢（Colletotrichum destructivum）是苜蓿炭疽病的主要病原菌之一。本试验研究了培养基、碳源、氮源、温度、pH、光照、湿度对毁灭刺盘孢菌菌丝生长、分生孢子产生和萌发的影响。结果表明：该菌菌丝适宜生长的培养基为PDA、PSA和V-8汁;适宜温度范围为28~36℃,最适温度为32℃;适宜pH范围为4~6。该病菌在PDA培养基上,分别以麦芽糖和蛋白胨为碳、氮源,在28℃,pH 6的条件下培养时其产孢能力最强。孢子萌发的最适碳、氮源分别为可溶性淀粉和牛肉膏、蛋白胨;最佳温度28℃;最适pH为6。相对湿度98%以上有利于孢子的萌发。持续光照利于菌丝生长、产孢和萌发。

Alfalfa anthracnose is a destructive disease in the alfalfa-planting areas, which was mostly caused by Colletotrichum destructivurn. The effects of medium, carbon, nitrogen, temperature, pH, illumination and humidity on the mycelial growth, sporulation and conidia germination of alfalfa anthracnose fungus were studied. The results showed that PDA, PSA and V-8 juice were the optimal medium for hyphal growth; the optimal tem- perature for mycelium growth ranged from 28℃ to 36℃, with the optimum temperature of 32℃ and the optimum pH of 4--6. The sporulation ability of C. destructivurn was best when it was cultured on PDA, with maltose and peptone as carbon and nitrogen sources, respectively, at 28℃and pH 6. For conidia germination, the optimal carbon and nitrogen sources were soluble starch, beef paste and peptone, and the optimal temperature was at 28~C ; the optimum pH value was 6. The 98% or higher relative humidity favored the conidia germination, while the continuous light was conducive to mycelial growth, sporulation and conidia germination.