油茶内生拮抗菌的筛选与鉴定

Screening and Identification of Oil-tea Endophytic Antagonistic Bacteria

[目的]通过对湖南长沙地区油茶内生拮抗菌的筛选,为油茶根腐病、叶枯病、炭疽病及软腐病的生物防治提供理论依据。[方法]采用研磨法从健康油茶根、茎、叶组织中分离出内生菌,通过平板对峙试验筛选出对油茶根腐病、叶枯病、炭疽病及软腐病都具有拮抗活性的内生菌,并进行形态观察和16S r DNA序列分析。[结果]不同组织内生细菌数量不同,根中内生细菌的数量最多,其次为茎,叶中最少。菌株J-3-1对油茶根腐病菌、叶枯病菌、炭疽病菌及软腐病菌均有拮抗活性,其抑菌圈半径分别为12.5、16.8、13.5、13.4 mm。16S r DNA相似性为99%。[结论]通过对该菌株进行形态观察及16S r DNA序列分析,鉴定其为枯草芽孢杆菌(Bacillus subtilis)。

[ Objective ] Through screening out oil-tea endophytic antagonistic bacteria in Changsha, the aim was to provide a theoretical basis for biological control of root rot, leaf blight, anthracnose and soft rot disease. [ Method] Using grinding method, endophytic bacteria was isolated from healthy root, stem and leaf of oil-tea. Through plate confrontation test, endophytic bacteria with antagonistic activity against oil-tea root rot, leaf blight, anthrax disease and soft rot disease was screened out, morphological observation and 16SrDNA sequence analysis was conducted. [ Result] The quantity of endophytic bacteria in different tissues of oil-tea was root 〉 stem 〉 leaf. Strain J-3-1 had antagonistic activities against root rot, leaf blight, anthrax disease and soft rot disease, the inhibitory zone radius was 12.5, 16.8, 13.5 and 13.4 mm, 16S rDNA similarity was 99%. [ Conclusion] By morphological observation and 16S rDNA sequence analysis, it is identified as Bacillus subtilis.