以高寒草地优势植物乳白香青(Anaphalis lactea)内生细菌RC14为研究对象,采用平板对峙法测定其对植物病原真菌的抑菌能力;并利用16SrDNA序列分析结合形态特征和生理生化特性对RC14进行鉴定。结果表明:RC14对多种植物根部病原菌和叶斑病菌均具有良好的抑制作用,抑制的病原菌种类有葡萄孢属(Botrytis)、蠕孢属(Bipolaris)、链格孢属(Alternaria)、镰孢菌属(Fusarium)和丝核菌属(Rhizoctonia)等植物病原真菌属,说明RC14具有较广的抑菌谱。RC14菌体杆状,大小为1.9~3.3μm×0.7~0.8μm,G+,中生芽孢,形态特征和生理生化特性及16SrDNA基因序列综合分析结果表明RC14为枯草芽孢杆菌(Bacillus subtilis)。本研究结果为开发和利用高寒草地所特有植物的内生拮抗菌提供了理论依据,为开发生物农药提供菌种资源。
The study is focused on the endophytic bacterium RC14 of dominant plant Anaphalis lactea in alpine grassland.Antimicrobial spectra of RC14 are determined using PDA-plate confrontation.Morphological,physiological and biochemical characteristics of RC14 are identified using 16S rDNA gene sequence analysis.Results show that RC14 has a capacity to inhibit roots pathogens and leaf spot pathogens in several varieties of plants,and can inhibit pathogenic fungi such as Bipolaris,Botrytis,Fusarium,Alternaria and Rhizoctonia indicating a wide antimicrobial spectrum of RC14.RC14 is gram-positive with 1.9~3.3 μm×0.7~0.8 μm rod-shape and can produce spore in the center.Morphological characteristics,physiological and biochemical characteristics and 16S rDNA gene sequence analysis show that RC14 is Bacillus subtilis.This study will provide evidence for exploring and utilizing antimicrobial endophytic bacteria in alpine grassland and will also provide strain resource for making biological pesticides.