一株拮抗细菌的鉴定及对植物炭疽病菌作用效果测定

摘要

Through morphological characteristics observation , physiological and biochemical characteristics measurement , as well as 16S rDNA and gyrB gene sequence determination , we ascertained the taxonomic status of an antagonistic bacterial strain SDF-005 isolated from the soil of walnut orchard , and tested the inhibitory activity of this strain to 5 plant anthracnose diseases and its control efficacy against walnut anthracnose in orchard .Strain SDF-005 was identified as Bacillus amyloliquefaciens.This strain had stronger inhibitive effect on the mycelial growth of 5 plant anthracnose diseases ( especially grape anthracnose disease ) , the inhibi-tion zone diameter ranged from 12.00 mm to 19.33 mm, and the inhibition rate reached 75.00%~83.06%.The inhibitive effect of SDF-005 against the pathogens of plant anthracnose was shown mainly by its effect on mycelia .The various metabolites of SDF-005 destroyed the structure of mycelial wall , and caused the expansion , distortion, warping and disintegration of mycelia .Using the 400~600-times dilution of SDF-005 WP to control walnut anthracnose in the forest , the control efficacy was above 75%.%采用形态特征观察、生理生化特性测定以及16S rDNA、gyrB基因序列测定，确定1株从核桃林地土壤中分离获得拮抗细菌菌株SDF-005的分类地位，并测定了该菌株对5种植物炭疽病的抑菌活性以及对核桃炭疽病的林间防治效果。经鉴定，该菌株为解淀粉芽孢杆菌Bacillus amyloliquefaciens。 SDF-005对5种植物炭疽病菌丝生长均具有较强的抑制作用，抑菌带直径均在12 mm以上，菌丝生长抑制率达75％以上，其中对葡萄炭疽病抑制作用最强，抑菌带直径为19．33 mm，菌丝生长抑制率为83．06％。 SDF-005对炭疽病菌的抑制作用主要表现为对菌丝的影响，SDF-005的各种代谢产物破坏病原菌菌丝壁结构，引起菌丝膨大、畸变、扭曲、菌丝壁消解。15亿/g SDF-005可湿性粉剂2个处理浓度田间防治核桃炭疽病效果均达75％以上。