蔬菜根际细菌R2-2的鉴定及其抑菌活性

Identification and antibacterial activity of antagonistic bacteria R2-2 from the rhizosphere of vegetables

从云南昆明市郊蔬菜根际分离细菌,经平板对峙培养筛选出1株抑菌能力较强的菌株R2-2,通过对其进行形态观察、Biolog微生物自动鉴定系鉴定和16S rDNA序列测定及其系统发育学分析,鉴定为甲基营养型芽孢杆菌(Bacillus methylotrophicus)。对R2-2与植物病原细菌(甘蓝黑腐病菌、魔芋细菌性软腐病菌、海棠斑点病菌、水稻白叶枯病菌、水稻细菌性条斑病菌)和病原真菌(疫霉菌、尖镰孢菌、茄镰孢菌、立枯丝核菌)进行对峙试验,结果显示,R2-2对水稻白叶枯病菌和水稻条斑病菌有较强的抑菌效果,抑菌圈直径分别达6.83 cm和7.03 cm。该菌株的16S rDNA序列已在GenBank中注册,登录号为JN648098。

Strain R2-2 antagonistic against the fungi and bacterial pathogen was isolated on NA and potato dextrose agar from the rhizosphere of vegetables from Kunming suburbs in Yunnan.On basis of phenotypic properties and Biolog automatic microbiology analysis system and on basis of 16S rDNA determination and analysis,strain R2-2 was identified to be B.methylotrophicus.In vitro antagonistic assay showed strain R2-2 could suppress the growth of five plant bacterial pathogens（Xanthomonas campestris pv.campestris,Erwinia carotovora subsp.carotovra,Xanthomonas campestris pv.begoniae,Xanthomonas oryzae pv.oryzae,Xanhomonas oryzae pv.oryzicola） an d four plant fungal pathogens（Phytophthora capsici,Fusarium oxysporum,Fusarium solani,Rhizoctonia solani）,and showed strong antibiosis activity to Xanthomonas oryzae pv.oryzae and Xanhomonas oryzae pv.oryzicola with inhibition zone diameter of 6.83 and 7.03 cm,respectively.16S rDNA sequence of the strain was registered in GenBank and the accession No.is JN648098.