惠兰(Cymbidium faberi)是中国兰属代表种之一, 具有很高的观赏价值和经济价值, 对其内生细菌进行研究不仅可以丰富植物内生细菌资源, 还可以为探讨兰花与微生物之间的相互作用关系提供基础数据。本研究采用分离培养方法及16S rRNA基因序列测定对天目山野生蕙兰、在温室培养1年后的蕙兰根内生细菌遗传多样性进行了研究。结果表明: 从野生蕙兰根内分离得到的97株细菌分属于变形菌门的α-变形菌纲、β-变形菌纲、γ-变形菌纲及厚壁菌门的13个属, 其最优势类群为γ-变形菌纲(86.60%), Lelliottia (26.80%)为最优势菌属。从温室盆栽蕙兰根内分离得到的52株细菌分属于变形菌门的α-变形菌纲、β-变形菌纲、γ-变形菌纲及放线菌门的9个属, 优势类群为β-变形菌纲(48.08%), 优势菌属为草螺菌属(Herbaspirillum) (34.62%), 其中菌株ehR17为潜在的新种。这些结果表明天目山野生蕙兰可培养根内生细菌多样性较其在温室培养1年后更为丰富, 同时也说明植物内生细菌的群落结构与生长环境密切相关。

Cymbidium faberi is a representative species of Cymbidium with high ornamental and economic value. Investigating the diversity of C. faberi’s endophytic bacteria not only enriches endophytic bacterial resources, but also provides basic data on orchid-microbe interactions. We investigated the genetic diversity of culturable endophytic bacteria in the roots of wild C. faberi from Tianmu Mountain, Zhejiang Province and C. faberi grown in a greenhouse for one year. Culture-dependent methods were used to isolate endophytic bacteria from the roots of C. faberi. The diversity of these bacteria was investigated using 16S rRNA gene partial sequence analysis. A total of 97 strains were isolated from the interior of wild C. faberi roots. Based on 16S rRNA gene sequences, the 97 isolates were affiliated with 13 genera of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Firmicutes. The dominant group was Gammaproteobacteria (86.60%), and the dominant genus was Lelliottia (26.80%). A total of 52 endophytic strains were isolated from the roots of C. faberi grown in the greenhouse. Based on 16S rRNA gene sequences, the 52 isolates were grouped into 9 genera of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Actinobacteria. The dominant group was Betaproteobacteria (48.08%), and the dominant genus was Herbaspirillum (34.62%). The strain ehR17 was identified as a potential novel species. For C. faberi, the diversity of culturable endophytic bacteria was higher from the wild Tianmu Mountain population than from plants grown in the greenhouse for one year. Community structure of endophytic bacteria was closely related to plant growth environment.