古井老枞茶树生态系统中细菌与真菌群落多样性特征分析

Bacterial and fungal diversity in the old tea plant ecosystem of Camellia sinensis ‘Fujian Shuixian’ cultivated in Gujing

摘要:

【目的】古井老枞经过漫长生长形成了独特“枞味”，而山场是茶叶品质形成的重要因素，微生物在山场生态系统的生物地球化学循环过程中可能起着关键作用，但老枞生态系统微生物群落组成特征还尚未明确。【方法】以生长于武夷山国家公园慧苑坑古井区域的老枞茶树为研究对象，采集茶树地上部叶片(叶际和叶内)和地下部土壤(根际、非根际和非茶园种植区空白)，分别以细菌16S rRNA基因和真菌内部转录间隔区(internal transcribed spacer, ITS)基因为分子标记，采用高通量测序技术分析其细菌和真菌群落组成特征。【结果】老枞茶树地上部细菌和真菌群落丰富度和多样性皆显著低于地下部。共现性网络中，各生态位网络的模块化指数均超过0.4，且微生物物种之间的协同作用大于竞争。门水平，变形菌(Proteobacteria)、酸杆菌(Acidobacteriota)、放线菌(Actinobacteriota)、子囊菌(Ascomycota)和担子菌(Basidiomycota)皆为地上和地下共有优势菌门(相对丰度>1%)，地上部变形菌、放线菌和子囊菌含量高于地下部，而酸杆菌和担子菌则相反(P<0.05)；属水平，优势物种中甲基杆菌(Methylobacterium-Methylorubrum)、鞘氨醇单胞菌(Sphingomonas)、假单胞菌(Pseudomonas)、氨杆菌(Amnibacterium)、芽胞杆菌(Bacillus)、枝胞菌(Cladosporium)和镰刀菌(Fusarium)是古井老枞各生态位主要的生物标记物。【结论】研究揭示了古井老枞茶树生态系统中不同生态位的细菌与真菌群落组成特征，可为今后深入研究老枞茶叶品质形成机理和茶树病害生物防治等相关功能菌种资源的应用提供科学参考。

Abstract:

[Objective] Over a prolonged period of growth, the old tea plant ecosystem of Camellia sinensis ‘Fujian Shuixian’ in Gujing has acquired a distinctive fir flavor, with the mountainous environment playing a key role in shaping the tea quality. Microbial communities play a vital role in biogeochemical cycling within mountainous ecosystems. Nevertheless, the characteristics of the microbial community within the distinct old tea plant ecosystem remain incompletely understood. [Methods] Samples were collected from both the aboveground and belowground parts of the old C. sinensis ‘Fujian Shuixian’ tea garden in Gujing, situated in the central region of the Wuyishan National Park. The samples encompassed the phyllosphere and leaf endosphere, along with soils from the rhizosphere, non-rhizosphere, and surrounding regions. High-throughput sequencing of the 16S rRNA gene and internal transcribed spacer (ITS) region were carried out to assess the bacterial and fungal diversity, respectively. [Results] The richness and diversity of bacterial and fungal communities in the aboveground part were markedly lower than those in the belowground part. Within co-occurrence networks, the modularity index for taxa networks in each niche exceeded 0.4, and the positive correlations in interactions among microbial taxa are greater than the competition. The prevailing phyla, with the relative abundance greater than 1%, were Proteobacteria, Acidobacteriota, Actinobacteriota, Ascomycota, and Basidiomycota, which were present in both above and belowground habitats. Notably, the relative abundance of Proteobacteria, Actinobacteria, and Ascomycetes aboveground surpassed that belowground, whereas that of Acidobacteria and Basidiomycetes displayed an opposite pattern (P<0.05). The prominent genera (with the abundance exceeding 1%) identified were Methylobacterium-Methylorubrum, Sphingomonas, Pseudomonas, Amnibacterium, Bacillus, Cladosporium, and Fusarium. These genera potentially served as crucial biomarkers in the ecological niches of C. sinensis ‘Fujian Shuixian’ within the old tea plant ecosystem in Gujing. [Conclusion] The present study unveiled the unique attributes of bacterial and fungal communities within the old tea plant ecosystem of C. sinensis ‘Fujian Shuixian’ in Gujing, delivering valuable scientific insights for disease prevention and biocontrol in tea plant cultivation, tea quality improvement, and the exploration of functional microbial resources.