普洱地区茶叶内生细菌与根际土壤细菌群落结构分析

Analysis on the community structure of bacteria in tea leaves and rhizosphere soil in Pu'er

摘要:

【目的】茶叶内生细菌、根际土壤细菌在普洱茶的发酵中起着重要的作用，还可以促进茶树生长，诱导茶树抗病性。研究其群落结构组成及相互关系可为微生物资源开发利用提供理论依据。【方法】本研究以普洱地区茶树叶片和根际土壤为材料，采用高通量测序技术，对茶叶及根际土壤细菌的16S核糖体RNA基因（16S rRNA）进行测序，比较分析茶叶与根际土壤细菌的群落结构组成。【结果】结果表明，茶叶内生细菌主要由76个属组成，归属于9个门。相对丰度较高的门是厚壁菌门（Firmicutes）、变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）、放线菌门（Actinobacteria）。相对丰度较高的属为乳杆菌属（Lactobacillus）、布劳特氏菌属（Blautia）、粪杆菌属（Faecalibacterium）、假单胞菌属（Pseudomonas）、红球菌属（Rhodococcus）、拟杆菌属（Bacteroide）和普雷沃氏菌属（Prevotella）。根际土壤细菌主要由198个属组成，归属于10个门，相对丰度较高的门是变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、绿弯菌门（Chloroflexi）和放线菌门（Actinobacteria）。相对丰度较高的属与茶叶中的高丰度属相似，但在两者中的相对丰度有所差异。茶叶内生细菌物种丰度和多样性显著低于根际土壤细菌，但超过50%的茶叶内生细菌同时存在根际土壤中。【结论】通过对普洱地区茶叶内生细菌及根际土壤细菌的群落结构组成分析，明确了茶叶内生细菌与根际土壤细菌的共性与差异，为普洱茶品质改良和生物菌肥开发研究奠定了基础。

关键词:茶树;茶叶内生细菌;根际土壤细菌;16S rRNA测序

Abstract:

[Objective] Endophyte and rhizosphere microorganisms of tea plant not only play an important role in the fermentation of Pu-erh tea, but also promote the growth of tea plants and induce disease resistance of tea plants. Studying the community structure and their relationship can provide a theoretical basis for the development and utilization of microbial resources. [Methods] In this study, we sequenced the 16S ribosomal RNA (16S rRNA) gene of bacteria in tea leaves and rhizosphere soil by high-throughput sequencing technology, analysed the community structure of bacteria in tea leaves and rhizosphere soil. [Results] The results showed that endophytic bacteria in tea leaves were mainly composed of 76 genera, belonging to 9 phyla. Among them, the phyla with higher relative abundance were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. At the genus level, the genera with high relative abundance were Lactobacillus, Blautia, Faecalibacterium, Pseudomonas, Rhodococcus, Bacteroide, and Prevotella. Rhizosphere soil bacteria were mainly composed of 198 genera, belonging to 10 phyla. The phyla with higher relative abundance were Proteobacteria, Chloroflexi, Actinobacteria, and Acidobacteria. At the genus level, the high abundance genera of bacteria in rhizosphere soil were the same as those in tea leaves, but the relative abundance of the same genus was different in the two. The abundance and diversity of endophytic bacteria in tea leaves were significantly lower than those in rhizosphere soil, but more than 50% of the endophytic bacteria were also identified in the rhizosphere soil. [Conclusion] Our findings would provide a basis for the bacterium-based strategies in bacterial manure and Pu-erh tea quality.

Key words:tea plant;endophytic bacteria in tea leaves;rhizosphere soil bacteria;16S rRNA sequencing