番茄叶霉病菌拮抗菌的筛选及其发酵条件

Selection of Antagonistic Microorganisms against Fulvia fulva and Analysis of Fermentation Conditions

从蔬菜地田间土壤中筛选出对番茄叶霉病具拮抗作用的22株菌株，其中14株细菌，8株放线菌。孢子萌发抑制试验表明，细菌X14菌株和放线菌F15菌株的发酵液及其离心后上清液对番茄叶霉病菌孢子萌发抑制率均达100％。菌丝生长抑制试验表明，X14菌株对番茄叶霉病菌的平均抑菌直径为22．2mm，初步鉴定该菌株为芽孢杆菌。利用离体叶片法测定对番茄叶霉病致病性的影响，结果表明，X14菌株对番茄叶霉病的防治效果为79．8％～89．0％。对X14菌株发酵条件研究，最佳碳源为淀粉，最佳氮源为NHaNO3，最适pH为6．0。

Twenty two strains （14 bacteria and 8 actinomyces strains） of antagonistic microorganisms against Fulvia fulva were isolated from vegetable field soil. Results showed that spore germination of F. fulva inhibited by fermented liquid and the supernatant of bacteria X14 and actinomyces F15 completely, the average inhibitory distance of strain X14 against mycelial growth reached to 22.2 mm, and its control effect on leaf mould of tomato was between 79.8 % and 89.0 %. According to the morphological feature, X14 was identified as Bacillus. The optimum carbohydrates nutrition, nitride nutrition and pH value was amylum, NH4NO3 and 6.0, respectively for X14 fermentation.