一株对大豆疫霉具有抑制活性放线菌的分离与分子鉴定

Isolation of a Actinomycete with Inhibitory Activity Against Phytophthora sojae in Soil

大豆疫霉(Phytophthora sojae)可引起大豆疫霉根腐病,是一种分布广泛、危害较为严重的世界性土壤传播病害。为获得对大豆疫霉根腐病具有良好抑制效果的放线菌资源,采用高氏培养基从采集自内蒙古多伦县的土壤中分离对大豆疫霉具有抑制活性放线菌并进行分子鉴定。结果表明:分离到一株对大豆疫霉具有较强抑制作用的放线菌,编号为放线菌1-17,平板对峙的抑菌直径在17.81mm以上。另外该菌对尖孢镰刀菌、禾谷镰刀菌也具有抑制作用,抑菌直径均在10mm以上。放线菌1-17的16SrDNA序列比对结果显示其与Streptomyces humidus NBRC 12877(T)相似性达99.85%,表明其为链霉菌属菌Streptomyces humidus sp.。

Phytophthora sojae can cause soybean root rot,which is a worldwide soil disease with general distribution and weighty harm.To screen the microbial resource with the inhibitory activity against P.sojae,soil from Duolun county in Inner Mongolia was selected to isolate actinomycetes by actinomycetes culture medium.The results showed that actinomycete 1-17 were obtained which had the inhibitory activity against P.sojae,a beyond 17.81 mm inhibitory diameter.In addition,the actinomycete 1-17 also showed inhibitory activity against other pathogen,beyond 10 mm inhibitory diameter.16 SrDNA sequence of actinomycete 1-17 had 99.85%similarity to Streptomyces humidus NBRC 12877（T）,and the result of molecular identification indicated that actinomycete 1-17 was Streptomyces humidus.