药用植物鸦胆子内生细菌分离及其抑菌活性研究

【目的】从药用植物鸦胆子中分离对植物病原真菌具有拮抗活性的内生细菌,为新型生物杀菌剂的开发提供依据。【方法】采用组织匀浆法对鸦胆子内生细菌进行分离,通过离体和活体组织抑菌试验筛选活性菌株;根据形态特征、生理生化测定、16S rDNA序列分析和Biolog系统对筛选获得的高活性菌株进行鉴定。【结果】从鸦胆子的根、叶、茎和果实部位分别分离得到43、19、15和8株内生细菌,其中分离自根部的YGB-11菌株对柑桔绿霉病菌、香蕉煤纹病菌等7种植物病原菌的抑菌率均超过80.00%,表现出较好的抗菌特性,结合形态特征、生理生化特征、16S rDNA序列分析和Biolog系统鉴定,确定YGB-11菌株为解淀粉芽孢杆菌(Bacillus amyloliquefacien)。【结论】内生细菌YGB-11菌株具有抑菌谱广、抑菌活性较高等特点,具有良好的应用前景。

Isolation of endophytic bacteria from medicinal plant Brucea javanica L. Merr. and its antifungal activity

[Objective]Endophytic bacteria with antagonistic activity were isolated from medicinal plant Brucea javanica L. Merr. to provide references for developing new biological fungicides. [Method]The endophytic bacteria were isolated by tis-sue homogenization and the strains with antifungal activity were screened by in vitro and in vivo antifungal tests. The strains with stronger inhibitory activity was identified based on morphology, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test. [Result]There were 43, 19, 15 and 8 isolates obtained from root, leaf, stem and fruit of Brucea javanica, respectively. Especially, the strain YGB-11 isolated from root showed good antibiosis characteristics with antibacterial rate over 80.00%to Penicillium digitatum (pers.ex Fr.)Sacc of Citrus green mold and Helminthosporium torulosum (Syd.) Ashby of banana helminthosporium leaf spot. Based on morphological, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test, the strain YGB-11 was identified as Bacillus amyloliquefacien. [Conclusion]With wide antimicrobial spectrum and high antifungal activities, YGB-11 has promising prospects.