草莓灰霉病菌拮抗放线菌的筛选及活性测定

Screening of Antagonistic Actinomycete Against Strawberry Grey Mould and Activity Determination of Its Fermentation Broth

以分离自新疆古尔班通古特沙漠土壤的放线菌为试材,采用琼脂块法和生长速率法,研究了供试放线菌对草莓灰霉病菌的抑菌活性;采用形态学特征、生理生化特性、16SrDNA序列分析等方法对筛选出的高活性拮抗菌株进行种类鉴定。结果表明:从141株放线菌中筛选出1株对草莓灰霉病菌的抑菌圈直径为20.67mm的高活性拮抗菌株XJ93。该菌株无菌发酵滤液对多种植物病原真菌具有明显抑制作用,抑菌率为25.00%~71.67%;80℃处理60min其抑菌率未见明显变化,在pH 5~9范围内其抑菌活性稳定,在可见光和紫外线照射150min内亦保持良好的抑菌活性。拮抗菌株XJ93经鉴定为唐德链霉菌(Streptomyces tendae)。拮抗放线菌XJ93具有广谱抑菌活性,对环境有良好的稳定性,可作为防治果蔬草莓灰霉病的生物农药潜力菌株进行开发应用。

The actinomycetes obtained from Gurbantunggut desert in Xinjiang were used as test material to study their inhibitory effect on strawberry grey mould using agar block and mycelia growth inhibition methods.The actinomycete with high antagonistic activity was identified based on morphological features,physiological and biochemical characters,and 16 SrDNA sequence analysis methods.The results showed that the antagonistic strain XJ93 with high activity was screened from141 actinomycetes,the inhibition diameter against grey mould reached 20.67 mm.The strain also displayed obvious inhibitory activities against many plant fungal pathogens with inhibition rates25.00%-71.67%.The culture filtrate of strain XJ93 showed good thermal stability,since the inhibitory rate was almost unchanged when the temperature rose to 80℃.The culture filtrate was also stable at pH 5-9,and maintained good inhibitory activity when exposed to a dose of light and ultraviolet irradiation for 150 minutes.The antagonistic actinomycete XJ93 was identified as Streptomyces tendae.It could be concluded that,S.tendae XJ93 had good inhibitory activity stability and broad inhibitory spectrum;therefore,it could potentially be used as biocontrol agent of plant fungal diseases including strawberry grey mould.