一株毛竹根部内生细菌SHEN20121的鉴定 及其对植物病原真菌的抑制作用

在分离鉴定毛竹(Phyllostachys edulis)根部相关内生菌的过程中，筛选得到具有生物活性的菌株SHEN20121。通过对其16S rDNA 序列的分析，结果显示其与类芽孢杆菌属中97个细菌的序列相似性为97%～99%；系统学分析显示该菌株与多粘类芽孢杆菌聚在一个分支上，bp支持率为 100，因此菌株SHEN20121被鉴定为多粘类芽孢杆菌（Paenibacillus polymyxa）。通过平板对峙实验证明了菌株SHEN20121对多种植物病原真菌：尖孢镰孢(Fusaricum oxysporum)，互隔链格孢(Alternaria alternata)，立枯丝核菌(Rhizoctonia solani)，灰葡萄孢(Botrvtis cinerea)，小孢拟盘多毛孢(Pestalotiopsis microspora)，柑橘青霉病菌(Penicillium italicum)均具有抑制作用，其中对灰葡萄孢，小孢拟盘多毛孢和柑橘青霉病菌的抑菌效果明显，尤其是首次发现对拟盘多毛孢属病原菌的抑制作用。作者认为该菌在生物农药方面具有潜在的应用价值，并可能将在植物病害的生物防治方面发挥重要作用。

Identification of endophytic bacterial strain SHEN20121 and its antibiotic activity against multiple plant pathogenic fungi

In this paper, a bacterial endophytic strain SHEN20121 was isolated from the roots of Phyllostachys edulis, and displayed high bioactivity against plant pathogenic fungi. Appraising with the analyses of 16S rDNA sequencing, the similarities of sequence between the SHEN20121 strain and other 97 registered bacterial strains of Paenibacillus were 97%-99%. The sequence alignments and phylogenic analysis showed strain SHEN20121 was closely related to Paenibacillus polymyxa and the bootstrap value was 100. SHEN20121 strain was found to have a strong antibiotic activity against six pathogenic fungi including Fusaricum oxysporum, Alternaria alternate, Rhizoctonia solani, Botrvtis cinerea, Pestalotiopsis microspora and Penicillium italicum by the dual-culture test. Inhibitory effect on Botrvtis cinerea, Pestalotiopsis microspora, Penicillium italicum were particularly significant. It is the first report on the resistance of Paenibacillus polymyxa to Pestalotiopsismicrospora. We concluded that the active strain SHEN20121 has potential ability in restraining plant pathogens and would be exploited as an attractive origins of new drug discovery and plant defense activator in the future.