放线菌F8对烟草黑胫病的拮抗作用及其产酶活性

从山东五莲于里黑胫病烟田健康烟株根际土壤分离到一株拮抗放线菌,编号为F8.为了科学评价该菌株在烟草黑胫病生防中的应用潜力,测定了其抑菌活性、产酶活性及控病效果,并通过形态学及16S rDNA序列分析研究其分类地位.结果表明,该菌株对于供试的烟草黑胫病菌具有较强的抑制作用,经无菌滤液处理后的菌丝生长畸形且停滞;该菌株具有几丁质酶、纤维素酶及蛋白酶活性.温室盆栽试验的防治效果显示接种后30 d,F8发酵液对烟草黑胫病的防效为70.3%;根据菌株形态特征、培养特性、生理生化特性及16S rDNA序列分析,鉴定该菌株为链霉菌属不产色链霉菌(Streptomyces achromogenes subsp. streptozoticus).

Antagonism Effect and Enzyme-producing Comparison of Actinomycetes F8 against Tobacco Black Shank

The strain F8, who isolated from rhizosphere of healthy tobacco, was an Actinomycete. In order to evaluate its application potential against tobacco black shank, tests for its inhibition activity, enzyme activity and effect on disease control were conducted in this study. The results showed that strain F8 had a strong antagonistic effect on P. parasitica var. nicotianae. The hyphal treated with culture filtrate of strain F8 sprouted abnormally and died. Besides these, strain F8 had enzyme-producing character of chitinase, cellulase and protease. After inoculated 30 d, it was founded that strain F8 could reduce the incidence of tobacco black shank by 70.3% in glasshouse experiments. According to the morphological, cultural, physiological and biochemical characteristics and 16S rDNA sequence, strain F8 was identified as Streptomyces achromogenes subsp. streptozoticus.