苦豆子内生拮抗放线菌的筛选及活性菌株鉴定

Screening and Identification of Antagonistic Endophytic Actinomycetes Isolated from Sophora alopecuroides L.

以6种植物病原真菌为靶标菌,采用皿内对峙培养法,对126株苦豆子内生放线菌进行了抗菌活性筛选。结果表明:15株菌具有较高的抑菌活性,占总菌株数11.9%,其中菌株YWZKDS4和NDZKDS65对稻瘟病病菌和黄瓜枯萎病菌的抑菌带宽度最大,分别为15.12mm和18.54mm;菌株NDZKDS22具有广谱抗菌活性,它们的抑菌带宽度均大于10mm以上;根据形态特征和16SrRNA基因序列同源性分析,3株活性菌株YWZKDS4、NDZKDS22、NDZKDS65分别与Streptomyces scabiei、Streptomyces albospinus和Streptomyces capillispiralis亲缘关系最近,序列相似性分别为99.1%、96.4%、98.8%。试验结果表明,苦豆子内生放线菌对6种植物病原真菌具有较好的抑菌活性。

Taking six kinds of plant pathogenic fungi as target bacteria,culture dishes method was adopted,antibacterial activity of 126 endophytic actionmycetes strains isolated from S. alopecuroides L. were tested. The results showed that 15 strains bad strong inhibiting effect on target pathogens,accounting for 11.9 % of total isolates. Of them,inhibition zones of YWLKDS4 against Pyricularia oryzae and NDZKI）S65 against Fusariurn oxysporum reached 15. 12 mm and 18. 54 mm respectively, NDZKDSez had broad-spectrum antifungal activity, their inhibition zones against 5 species of target pathogens were more than 10 mrn. The closest genetic relationships of YWZKDS4 with Streptomyces scabiei, NDZKDS22 with S. albospinus, and NDZKDS65 with S. capillispiralis were found respectively by morphological characteristics and 16S rRNA sequence similarity analysis. Sequence similarity were 99. 1%, 96. 4%, 98. 8%. According to the experiment, the antimicrobial activity of endopbytic actinomycetes from S. alopecuroides L. against 6 species of target plant pathogens was better.