马唐生防真菌弯孢霉(Curvularia sp.)菌株QZ-200的生物学特性研究

The biological characteistics of strain QZ-200 of curvularia sp.for controlling Digitaria sanguinalis

本文主要研究影响马唐生防菌弯孢霉(curvularia sp.)菌株QZ-200营养生长、孢子萌发及孢子形成的因子。该菌在SCS(黄豆粉-玉米粉-蔗糖)培养基上生长最好;生长温度为10～40℃,最适为28℃;pH为2～11,最适pH为6;在以葡萄糖为碳源、以磷酸氢二铵为N源的Czapek培养基上生长良好。分生孢子萌发的温度为10～45℃,最适为28～30℃,失活温度为52℃10min;pH为2～11,适宜为5～8;以自由水或饱和湿度条件下萌发率最高;1％蛋白胨、1％牛肉浸膏、0.1％的TW-80、1％马唐煎汁和0.2％的菜籽油溶液明显提高萌发速度。该菌孢子形成的温度为15～35℃,最适为28℃;连续光照比光暗12h交替处理更有利于产孢,黑光灯为最佳光源。

Factors influencing vegetative growth, conidial germination and sporulation of strain QZ-200 of Curvularia sp. , a biological control agent for crabgrass (Digitaria sanguinalis ), had been primarily studied. SCS (soyflour-cornmeal-su- crose) was the best medium for vegetative growth tested so far. The ranges of temperature and pH for mycelial growth were 10-40℃ and 2-11, the optimum were 28℃ and pH 6 respectively; the fungus grew better in Czapek medium with glucose as carbon source and (NH_4)_2HPO_4 as nitrogen source. The ranges of temperature and pH for conidial germination of strain QZ-200 were 10-45℃ and 2-11, the optimum were 25-30℃ and pH 5-8; under RH 100% or in free water, the percentage of conidial germination was the highest and the germination was stimulated by adding of peptone, beef extract, TW-80, crabgrass extract or rapeseed oil to the media. The range of temperature for sporulation was 15-35℃, the optimum was 28℃; the continuous illumination gave better result than an alternating of light and darkness for 12 hours, and the black fluorescent light was the best illumination for sporulation.