大豆灰霉病和黑斑病拮抗菌株的筛选和鉴定

Screening and identification of antagonistic strains of soybean Botrytis cinerea and Alternaria tenuissima

生物防治病虫害是当前农业可持续发展的重要方向之一。大豆灰霉病(Botrytis cinerea)和黑斑病(Alternaria tenuissima)是大豆上的主要病害,为了控制灰霉病和黑斑病对大豆的危害,通过生物防治的方法,采用土壤稀释法从江西省东乡野生稻根际土壤中分离获得64株拮抗菌,经反复筛选及平板对峙法测定菌株A2、A6、A10、F7和G6对大豆灰霉病菌和黑斑病菌有稳定拮抗作用。通过菌株发酵滤液和化学农药抑菌效果比较,菌株发酵液的抑菌率远超化学农药,其中拮抗菌的发酵滤液对灰霉病最佳抑制率达91.7%,对黑斑病最佳抑制率在60.9%~87.0%之间;而灰霉病特效素和苯醚甲环唑对灰霉病和黑斑病的最佳抑制率仅为68.0%和47.3%。根据菌株的生理生化特征及16S rDNA分子鉴定,5株菌分别为米修链霉菌(Streptomyces misionensis)、绛红产色小单孢菌(Micromonospora purpureochromogenes)、圈卷产色链霉菌(Streptomyces ansochromogenes)、链霉菌(Streptomyces sp.)和类芽孢杆菌(Panenibacillus sp.)。本研究为大豆灰霉病和黑斑病的生防菌开发和利用提供了一定的支撑。

Bio-control for inhibiting pests and diseases is one of the important approaches for sustainable agricultural development.Botrytis cinerea and alternaria tenuissima are two main soybean diseases.In order to better control Botrytis cinerea and Alternaria tenuissima,we isolated 64 strains of antagonistic bacteria from the rhizosphere soil of wild rice in Jiangxi Province by soil dilution method.The results showed that A2,A6,A10,F7 and G6 strains were with stable antagonism against Botrytis cinerea and Alternaria tenuissima by repeated screening and plate confrontation assay.The inhibition rate of the antagonistic fermentation filtrate was much higher than that of the chemical pesticide.The optimal inhibition rate of the antagonistic fermentation filtrate against Botrytis cinerea and Alternaria tenuissima was 91.7%and 60.9%-87.0%,respectively;while that of the chemical pesticides was only 68.0%and 47.3%,respectively.By analysis of strain physiological and biochemical characteristics as well as the identification of 16S rDNA,we determined that five strains were Streptomyces misionensis,Micromonospora purpureochromogenes,Streptomyces ansochromogenes,Streptomyces species,and Panenibacillus species.This study would provide technical support for the development and utilization of bio-control bacteria in controlling soybean Botrytis cinerea and Alternaria tenuissima.