甘草内生细菌的分离及拮抗菌株鉴定

Isolation of Endophytic Bacteria from Glycyrrhiza and Identifying of Antagonistic Bacteria

摘要:

从乌拉尔甘草健康植株的根茎叶中共分离到内生细菌98株，经初步鉴定芽孢杆菌属（Bacillus sp.）为优势种群，约占30%；从不同生长年份甘草的根、茎、叶组织中分离内生细菌种群密度从5.0×10⁴ cfu/g～2.9×10⁷ cfu/g鲜重不等。采用平板对峙方法筛选出6株对植物病原菌有明显体外拮抗活性的菌株，通过菌落、菌体形态观察、生理生化反应及16S rDNA序列分析，同时结合Biolog细菌自动鉴定系统验证，鉴定这6株拮抗菌分属萎缩芽孢杆菌(Bacillus atrophaeus)、多粘类芽孢杆菌(Paenibacillus polymyxa)、枯草芽孢杆菌(Bacillus subtilis)、Paenibacillus ehimensis。

Abstract:

98 endophytic bacteria strains were isolated from different internal tissues of Glycyrrhiza uralensis plants collected from Innermongolia region. Results indicated that the population densities of endophytic bacteria ranged from 5.0×10⁴cfu/g～2.9×10⁷cfu/g fresh weight although it varied depending on tissue of the plant. Among these strains, Bacillus sp. was the most prevalent endophytic bacterium, which was amount to 30%.Of the 98 isolates, 6 strains exhibited extensive antagonistic activities against pathogenic bacteria. Characterization showed that these bacteria were Bacillus atrophaeus、Paenibacillus polymyxa、Bacillus subtilis、Paenibacillus ehimensis. This study indicated that selected 6 endophytic bacteria strains have potential for biological control of plant disease.