茶轮斑病对茶树叶片内生真菌群落结构的影响

目的] 茶树叶片内生真菌长期与茶树协同进化，互利共生，在生物和非生物胁迫的生态系统中对茶树起着重要的保护作用，其群落结构组成相对稳定，但在外界因素的影响下，也会发生一定的变化。然而，关于生物胁迫对茶树叶片内生真菌群落结构的影响还缺乏系统的研究。因此，对生物胁迫下叶片内生真菌群落结构的多样性研究具有重要意义。方法] 本研究采用高通量测序技术，测序了茶轮斑病发病茶树叶片和健康茶树叶片的内生真菌ITS rRNA基因的ITS1区序列，对比分析了内生真菌的多样性和群落结构组成。结果] 结果表明，发病组叶片的内生真菌多样性和物种丰度均低于健康组。在门分类水平上，2组样本的优势菌群均为子囊菌门（Ascomycota），在属分类水平上，发病组的优势菌群为炭疽菌属（Colletotrichum）和假拟盘多毛孢属（Pseudopestalotiopsis），而健康组的优势菌为枝孢属（Cladosporium）。此外，2组样本内生真菌在群落结构组成上也有显著差异，发病组中假拟盘多毛孢属（Pseudopestalotiopsis）、炭疽菌属（Colletotrichum）和节菱孢属（Arthrinium）的相对丰度显著高于健康组，健康组中被孢霉属（Mortierella）、曲霉属（Aspergillus）、织球壳菌属（Plectosphaerella）、Lectera、葡孢霉属（Botryotrichum）、青霉菌属（Penicillium）、赤霉属（Gibberella）、毛壳菌属（Chaetomium）、Lulwoana和轮枝孢属（Verticillium）的相对丰度显著高于发病组。结论] 综上，茶轮斑病的发生改变了茶树叶片内生真菌的群落结构，使少数物种优势生长。通过研究，明确了真菌病害对茶叶内生真菌群落结构的影响，为病菌的致病机理研究奠定基础，为茶树病害防治提供理论依据。

Effects of tea grey blight on the community structure of endophytic fungi in tea leaves

Objective] Coevolution and mutualism have existed between endophytic fungi and tea plants for a long time. They play an important protective role in the ecosystem of biotic and abiotic stress. Their community structure composition is relatively stable and has certain changes under the influence of external factors, but the effect of biotic stress on endophytic fungi community structure of tea leaves is still lack of systematic research. Therefore, it is necessary to study the diversity of endophytic fungi community structure under biotic stress.Methods] We sequenced the ITS1 region of ITS rRNA genes of endophytic fungi in tea leaves of the diseased group and healthy group by high-throughput sequencing technology, and the microbiota composition and diversity were compared and analyzed.Results] The results showed that the diseased group had lower endophytic fungal diversity and microbial community richness than those of the healthy group. At the phylum level, Ascomycota was dominant in both of them. At the genus level, Colletotrichum and Pseudopestalotiopsis were dominant in diseased group samples, Cladosporium was dominant in healthy group samples. In addition, there were significant differences in community structure composition of endophytic fungi between the two groups. The relative abundance of Pseudopestalotiopsis, Colletotrichum and Arthrinium in diseased group was significantly higher than that of the healthy group. However, the relative abundance of Mortierella, Aspergillus, Plectosphaerella, Lectera, Botryotrichum, Penicillium, Gibberella, Chaetomium, Lulwoana and Verticillium in diseased group were significantly lower than that of the healthy group.Conclusion] The occurrence of tea grey blight changed the community structure of endophytic fungi in tea leaves and made a few species grow preferentially. These results provide insights into the effect of fungal diseases on the endophytic fungal community structure of tea leaves, and also lay the foundation for the pathogenic mechanism of the pathogen and provide the theoretical basis for the prevention and control of tea plant diseases.