天然香料植物油樟叶可培养内生细菌群落结构与多样性

Structure and diversity of culturable endophytic bacteria in natural spice Cinnamomum longepaniculatum(Gamble) N. Chao leaves

该文旨在研究天然香料植物油樟叶内生细菌群落组成。利用传统平板分离法对春夏秋冬4个季节油樟叶内生细菌进行分离,并通过形态观察挑取166株有代表性的菌株进行基于16S rDNA基因序列的系统发育和多样性分析。结果表明,不同季节油樟叶片中的内生细菌数量在0.7×10^3~4.5×10^4 CFU/g,其中秋季的数量最多。扩增16S rDNA基因序列鉴定所得菌株可分为3个门13个属40个种,其中春季9个属23个种,夏季4个属4个种,秋季5个属11个种,冬季1个属2个种,4个季节优势菌均为芽胞杆菌(Bacillus),且不同季节的内生细菌种群数量、均匀度、优势度存在差异,秋季群种类较丰富,优势属突出,且分布均匀,冬季多样性、优势度和均匀度较低。该研究为进一步挖掘油樟与其内生菌之间的互作关系提供参考依据,可为深入研究油樟叶内生菌与其物质代谢和樟油合成调控提供供试菌种资源基础。

The purpose of this study was to investigate the composition of endophytic bacterial communities in Cinnamomum longepaniculatum(Gamble)N.Chao leaves.A total of 166 representative strains were selected by morphological observation,followed by performing phylogenetic and diversity analyses based on 16S rDNA sequence.The results revealed that the population of endophytic bacteria varied between 0.7×10^3 and 4.5×10^4 CFU/g in leaves collected in different seasons,with the largest population observed in autumn.Strains identified were divided into 3 phyla,13 genera,and 40 species.Nine genera and 23 species were identified in spring,four genera and four species identified in summer,five genera and 11 species found in autumn,and one genus and two species found in winter.Additionally,strains from genus Bacillus was the dominant bacteria in all samples.The leaves collected in autumn had abundant species,and the dominant genera were prominent and evenly distributed.In comparison,the diversity,dominance and evenness of endophytic bacteria in winter leaves were low.This study provides the groundwork for further exploration of the interactions between Cinnamomum longepaniculatum(Gamble)N.Chao leaves and symbiotic endophytic bacteria,as well as for investigating its metabolites and controlling essential oil synthesis.