西瓜枯萎病高效拮抗菌XJUL-12的筛选与鉴定

目的:分离获得西瓜枯萎病高效拮抗菌,为研究西瓜枯萎病高效拮抗菌的拮抗机制奠定基础。方法:用碾碎法从新疆有毒植物麻(Urtica cannabina L.)、亚洲薄荷(Mentha asiatica Boris.)、阿尔泰藜芦(Veratrum lobelianum Bernh.)中分离内生菌,并用琼脂扩散法筛选出对西瓜枯萎病具有较强抗性的内生菌XJUL-12,通过PCR方法扩增XJUL-12的16S rDNA,并与GeneBank中已鉴定菌的16S rDNA序列对比,用N-J方法构建XJUL-12进化树,用Bootstraping法对其评估,同时结合其形态特征、生理生化检测、G C mol%含量对XJUL-12进行鉴定。结果:XJUL-12的16S rDNA序列与Bacillus subtilisstrain CGMCC1869同源性为99%,G C mol%含量为46.72mol%。结论:筛选获得的内生菌XJUL-12对西瓜枯萎病具有较强抗性,并将XJUL-12鉴定为枯草芽孢杆菌。

Characteristics and Identification of An Antagonistic XJUL- 12 Against Fusarium Wilt of Watermelon

Objective:Isolate the highest antagonistic activity against Fusarium wilt of watermelon for research the mechanism of the bacteria against fusarium wilt of watermelon.Methods:The endophyte was isolated from the poisonous Urtica cannabina L.,Mentha asiatica Boris.and Veratrum lobelianum Bernh.in Xinjiang,The XJUL-12 strain showed the highest antagonistic activity against Fusarium wilt of watermelon with by agar diffusion tests.The 16S rDNA gene sequence was amplified by PCR.PCR products was sequenced and the DNA sequence was blasted on GeneBank.The phylogenetic tree of XJUL-12 was constructed with neighbor-joining method and the relation of XJUL-12 and other bacilli was evaluated by using Bootstrap,Based on the results of morphological,physiological and chemotaxonomic characteristics,and G C mol% content,the XJUL-12 was identified.Results:The sequence analysis of the 16S rDNA showed that XJUL-12 was closely related to Bacillus subtilis strain CGMCC1869,with the similarity of 98%.The G C mol% content of XJUL-12 is 46.72 mol%.Conclusion:The XJUL-12 was identified as Bacillus subtilis and ofered potential material for studies of the mechanism of against Fusarium wilt of watermelon in the watermelon.