油茶内生拮抗细菌Y13的定殖能力及其对土著细菌的影响

Colonization of Bacillus subtilis Y13 in Camellia oleifera Leaves and Its Effect on Native Bacteria

采用抗利福平标记法,定期取样、平板稀释法回收等方法,检测拮抗菌株Y13在油茶叶片内的定殖能力;以平板培养及16S rDNA法分析菌株Y13对油茶叶片内土著细菌种群的影响,为油茶炭疽病的生态治理提供理论依据。结果表明,菌株Y13在油茶健株和病株叶内均能稳定定殖,接种30 d时仍分别能检测到6.60×103CFU/g和3.56×103 CFU/g的标记菌株;油茶叶片内可培养内生细菌主要属于5个属的7个已知种,分别为芽孢杆菌属(Bacillus)、赖氨酸芽孢杆菌属(Lysinibacillus)、克雷伯菌属(Klebsiella)、鞘氨醇菌属(Sphingomonas)和假单胞菌属(Pseudomonas),以芽孢杆菌属和赖氨酸芽孢杆菌属为优势属。菌株Y13对不同处理油茶叶片内的群落结构和数量有明显的影响,能促进土著细菌群体的多样性,同时能够显著提高油茶叶片内的枯草芽孢杆菌数量,有利于抑制油茶炭疽病病原菌的增长。

The colonization capacity of strain Y13 in the Camellia oleifera, was investigated by marking with rifampicin, periodical sampling, and recovering bacteria through diluting-plate method, as well as the effects of Y13 on native bacterial population were also studied by diluting-plate and 16S rDNA methods, which would provide a basis for ecological control of camellia anthracnose. The results showed strain Y13R displayed good colonization in camellia oleifera, 30 days after inoculation, 6.60×103CFU/g and 3.56×103CFU/g strains Y13R could be detected in healthy and diseased leaves, respectively. Endophytic bacteria isolated from Camellia oleifera belong to 5 genera of 7 species, Bacillus, Lysinibacillus, Klebsiella, Sphingomonas and Pseudomonas, Bacillus and Lysinibacillus was the most prevalent genera. The group and amount of predominant species had evident distinction in healthy and diseased leaves. The diversities of bacteria in the Camellia oleifera leveas were improved by Y13 treatment and suppressed the pathogen propagation.