番茄内生拮抗细菌的分离鉴定及培养条件研究

Identification and culturing conditions of endophytic antagonistic strains associated with tomato

针对番茄生产上灰霉病和叶霉病两大病害,为寻找安全、高效无污染的生防菌株及其最佳培养条件,本试验采用组织分离法从健康的番茄植株中分离出642个内生细菌菌株,并采用平板对峙法筛选出对番茄灰霉病菌和叶霉病菌拮抗作用强且稳定的两个菌株Thyy1和Jcxy8。通过形态学观察及生理生化特征测定,初步鉴定Jcxy8属环状芽孢杆菌(Bacillus circulans),菌株Thhy1属枯草芽孢杆菌(Bacillus subtilis)。内生拮抗细菌在以豆饼粉为原料的6号培养基中生长速度快,发酵滤液对两种病原菌的抑制作用强。培养基初始pH值、培养时间、温度、通气量等对菌株生长及其抗菌物质的分泌有明显影响。以豆饼粉培养基、初始pH6.7、培养时间48h、温度30℃、并尽量增大培养通气量为菌株的最佳培养条件。

To search for a safe, effective and non-polluting bio-control microbe of tomato gray mould and tomato leaf mould, 642 endophytic bacterial strains were isolated from healthy tomato plants by tissue-isolation method. Two antagonistic strains of endophytic bacteria Thyyl and Jcxy8, with strong and steady antagonistic effect on Botrytis cinerea and Fulvia fulva were selected by plat-confront method. Thyyl and Jcxy8 are preliminarily identified as Bacillus circulans and Bacillus subtilis, respectively, based on physiological and biochemical character measurement. The cultivating medium and conditions of Thyyl and Jcxy8 strains were then studied. Results indicate that the optimum medium for culturing comprises of a well-ventilated soybean powder with an initial pH of 6.7, duration of 48 h and temperature of 30℃.