水稻胡麻斑病土壤拮抗菌的筛选·鉴定及抑菌谱分析

Screening,Identification and Antibacterial Spectrum of Soil Antagonistic Bacteria against Rice Brown Spot

[目的]从土壤中筛选对水稻胡麻斑病病原菌(Helminthospotium oryzae Breda de Hann)具有稳定拮抗作用的细菌。[方法]利用稀释平板法对从土样中分离出的细菌进行拮抗菌的初筛,再采用室内平板筛选法进行复筛。将拮抗效果最佳的菌株进行培养,通过菌体形态特征观察和生理生化测试进行菌种鉴定,并采用平板对峙法进行拮抗菌的抑菌谱分析。[结果]从38份土样中分离了494株细菌,初筛获得拮抗菌株24株,复筛得到4株拮抗能力较强的菌株,经鉴定4种拮抗菌均为地衣芽孢杆菌属(Bacillus licheniformis),并得到其抑菌谱。[结论]为利用拮抗菌生物防治水稻胡麻斑病提供了理论依据。

[ Objective ] To screen the antagonistic bacteria which could resist rice brown spot from soil. [ Method ] The dilnted plate method was used for preliminary screening of antagonistic bacteria from soil. Indoor plate screening method was used for secondary screening. The best antago- nist strains were cultivated and identified according to their morphology and biochemical and physiological features. Plate confrontation method was used for antibacterial spectrum. [ Result] 24 antagonistic strains were screened out from 494 strains which were selected from 38 soil samples by preliminary screening and four antagonistic bacteria （AⅢ, FⅠ, HⅠ and HⅡ）with strongest antagonistic effect were screened, all the four strains were finally identified to be Bacillus licheniformis ,whose antibacterial spectrum was obtained. [ Conclusion] The study provides theoretical support for the biological control of rice brown spot disease by antagonistic bacteria.