樟属柠檬醛型树种内生真菌的群落结构分析

Analysis of the endophytic fungal community in Camphora tree species with the citral chemotype

关键词:  宿主化学型，内生真菌，高通量测序，物种多样性，群落组成

Key words:  chemotype of host species, endophytic fungi, high-throughput sequencing, species diversity, community composition

摘要:

为研究樟属3种柠檬醛型树种内生真菌群落多样性，探究相同化学型不同树种及不同组织部位内生真菌的多样性、结构差异。该文通过高通量测序的方法分析了36个样本，共获得序列2 207 878条。结果表明：（1）樟属柠檬醛化学型不同树种的内生真菌群落在物种组成上差异显著且内生真菌物种组成在根、茎、叶中展现出器官偏好性和多样性。（2）Chao和Ace指数的排序一致，均为樟（Camphora officinarum）（QCA）>猴樟（C. bodinieri）（QBO）>黄樟（C. parthenoxylon）（QPO）。这表明樟的内生真菌物种丰富度最高，其OTU数量690；黄樟的物种丰富度最低，OTU数量为414。而Shannon多样性指数的排序为QPO>QBO>QCA，Simpson多样性指数则与之相反，由此可知，樟的内生真菌群落多样性最小。（3）由Bray-Curtis距离的主坐标分析（PCoA）可知，猴樟和黄樟的样本点聚集紧密，表明二者的内生真菌群落结构相似度较高；而这两种植物与樟的样本点分布相对分散，因此它们与樟的内生真菌群落结构相似度较低。（4）樟属3种柠檬醛型树种均表现为叶和茎内生真菌的群落结构相似，以及根与叶的内生真菌的群落差异较大。该结果表明宿主树种与组织部位异质性的共同作用塑造内生真菌群落，为筛选樟属柠檬醛型树种中的探索潜在功能内生真菌奠定了基础，为内生真菌群落与宿主树种及化学型的协同进化关系提供了参考。

Abstract:

To investigate the community diversity of endophytic fungi in three citral chemotype tree species in the Camphora, and explore the diversity and structural differences of endophytic fungi in different tree species with the same chemotype and various tissue parts, this study utilized high throughput sequencing to analyze 36 samples, a total of 2 207 878 sequences were obtained. The results were as follow: (1) The endophytic fungal communities of different tree species with the citral chemotype in the Camphora exhibited significant differences in species composition, and the endophytic fungal species composition showed organ preference and diversity in roots, stems, and leaves. (2) The ranking of the Chao and Ace indices was consistent, all showing Camphora officinarum (QCA) >Camphora bodinieri (QBO) > Camphora parthenoxylon (QPO). This indicated that Camphora officinarum had the highest species richness of endophytic fungi, with 690 OTUs, while Camphora parthenoxylon had the lowest species richness, with 414 OTUs. In contrast, the Shannon diversity index showed the order QPO > QBO > QCA, and the Simpson diversity index exhibited the opposite trend. Thus, it could be concluded that the endophytic fungal community diversity of Camphora officinarum was the lowest. (3) Principal coordinate analysis(PCoA)based on Bray-Curtis distances revealed that the sample points of Camphora bodinieri and Camphora parthenoxylon were closely clustered, indicating a high similarity in their endophytic fungal community structures. In comparison, the sample points of these two species were relatively dispersed from those of Camphora officinarum, suggesting a lower similarity in endophytic fungal community structure between them and Camphora officinarum. (4) The three citral chenmotype tree species of the Camphora all exhibited similar community structures of endophytic fungi in leaves and stems, while showing significant differences in the fungal communities between roots and leaves. The results indicated that the combined influence of host tree species and tissue heterogeneity shape the endophytic fungal community, laid a foundation for exploring potential functional endophytic fungi in citral chemotype tree species of the Camphora and provided insights into the co-evolutionary relationship between endophytic fungal communities and host tree species and chemotypes.