纠敏 李晶晶 李伟山 冯辉 刘瑞显 魏利辉 周冬梅

摘要：   為了开发对大豆疫霉病病菌具有拮抗作用的放线菌资源，从健康大豆根际土壤中分离筛选获得2株对大豆疫病具有显著抑制效果的生防放线菌菌株JAX-13和JAX-14。经生理生化和分子生物学鉴定，菌株JAX-13和JAX-14分别为放线菌属细菌（ Actinomycetales bacterium ）和链霉菌（ Streptomyces ）。平板拮抗试验结果表明，2种菌株对大豆疫霉病病菌的抑制率分别为56.26%和50.06%;光学显微镜观察发现，菌株JAX-13和JAX-14发酵液处理的大豆疫霉病病菌菌丝排列杂乱无章，菌丝生长受到抑制并且菌丝内部出现原生质聚集成块现象。盆栽试验结果表明，经菌株JAX-13和JAX-14发酵液处理的大豆对大豆疫霉病病菌的防效分别达56.56%和72.22%，且菌株发酵液对大豆植株具有一定的促生作用。总体来看，菌株JAX-13和JAX-14生防效果优良，是2种具有潜在应用价值的放线菌。

关键词：  放线菌; 链霉菌; 生物防治; 大豆疫病; 大豆疫霉病病菌

中图分类号：  S482.2 +92    文献标识码： A    文章编号：  1000-4440（2021）05-1137-06

Screening， identification and biocontrol effect of actinomycetes against  Phytophthora sojae

JIU Min  1 ， LI Jing-jing  1，2 ， LI Wei-shan  1，2 ， FENG Hui  2 ， LIU Rui-xian  3 ， WEI Li-hui  2 ， ZHOU Dong-mei  2

（1.College of Food and Bioengineering， Henan University of Science and Technology， Luoyang 471023， China; 2.Institute of Plant Protection， Jiangsu Academy of Agricultural Sciences， Nanjing 210014， China; 3.Institute of Industrial Crops， Jiangsu Academy of Agricultural Sciences， Nanjing 210014， China）

Abstract：  To develop actinomycete resources with antagonistic effect on  Phytophthora sojae ， two strains of biocontrol actinomycetes JAX-13 and JAX-14 were isolated and screened from healthy soybean rhizosphere soil， which had significant inhibitory effect on soybean  Phytophthora  blight. Through physiological， biochemical analysis and molecular biology identification， strains JAX-13 and JAX-14 were identified as  Actinomycetales bacterium  and  Streptomyces ， respectively. The results of plate confrontation test showed that， the inhibition rates of two strains to  P. sojae  were 56.26% and 50.06%， respectively. Through optical microscope observation， it was found that the hyphae of  P. sojae  treated by the fermentation broth of JAX-13 and JAX-14 strains arranged disorderly， the growth of hyphae was inhibited and the protoplasm in hyphae gathered into lumps. The results of pot experiment showed that， after treated with fermentation broth of JAX-13 or JAX-14 strain， the control effects of soybeans against  P. sojae  were 56.56% and 72.22%， respectively， and the fermentation broth showed some promoting effects on the growth of soybean plants. In general， strains JAX-13 and JAX-14 are two kinds of actinomycete with good biocontrol effect and show potential application value.

Key words：  actinomycete;  Streptomyces ; biological control; soybean blight;  Phytophthora sojae

大豆疫病是由大豆疫霉菌（ Phytophthora sojae ）感染引起的一种分布范围广、危害极其严重的全球性土传病害，防治十分困难  [1-2] 。大豆疫霉病病菌在大豆的整个生育期内都可以进行侵染，造成种子、根、茎等腐烂，植株枯死，大豆产量严重损失  [3] 。大豆疫病防治的最有效方法是选育抗病品种，但是其抗病资源极为有限  [4] 。目前，预防和控制疫病主要依赖化学防治方法，但化学防治方法的长期使用会造成农药残留、环境污染、危害人类及动物健康等问题  [5] 。生物防治方法利用微生物资源来防治植物病害，具有绿色、安全、无污染等特点，是一种具有发展潜力的防治方法  [6] 。……