拮抗茄子黄萎病菌土壤放线菌的分离筛选和鉴定

为了研究土壤拮抗性放线菌对茄子黄萎病的生防价值,从陕西省延安市宝塔区与汉中地区土壤中分离、纯化获得154株具有纤维素降解活性的放线菌。采用平板对峙培养法进行初筛,用生长速率法对抑菌效果较好的菌株ZX-10-4进行抑菌谱的测定,并进行盆栽试验验证其对茄子黄萎病的防治效果,通过形态、培养特征及16S rDNA序列分析研究其分类地位。结果显示,有17株放线菌对茄子黄萎病菌抑菌效果较好且抑菌活性稳定,其中菌株ZX-10-4的抑菌活性最高,抑菌率达90.15%;活性菌株ZX-10-4发酵原液对茄子黄萎病的保护和治疗作用分别为70.00%和60.33%,稀释5倍液的防效也在50%以上。根据形态、培养特征、生理生化指标和16S rDNA序列分析,初步确定菌株ZX-10-4为白网链霉菌Streptomyces albireticuli的近似种。

Screening and identification of actinomycetes on Verticillium dahliae from soil

In order to confirm the potential of antagonists for biological control against Verticillium dahliae,154 actinomycetes which can decompose cellulose were isolated from the soil of Yan’an District and Hanzhong District of Shaanxi Province in China.The plate-confrontation method and growth speed rate method were used for preliminary screening and antimicrobial test in vitro.Pots trails were carried out to assess the inhibitory activity of strain ZX-10-4 in vivo.The taxonomic identification of strain ZX-10-4 was studied through its morphology,culture characteristics,chemotaxonomic tests and 16S rDNA sequence alignment.Results showed that 17 strains of actinomycetes exhibited good and stable inhibition activity against V.dahliae,and ZX-10-4 showed 90.15% inhibition rate.The protective and the therapeutic efficacy of the aseptic filtrate of ZX-10-4 reached to 70.00% and 60.33% with no dilution,and more than 50% in 5 times dilution in pots trails,respectively.Based on the identification methods used,strain ZX-10-4 was grouped into the genus Streptomyces and identified as a similar species to S.albireticuli.