不同生长状态祁连圆柏针叶内生真菌群落结构与多样性分析

Community structure and diversity analysis of endophytic fungi in needles of Juniperus przewalskii

为掌握西北干旱地区祁连圆柏内生真菌群落结构以及多样性,探索内生真菌与祁连圆柏针叶生长状态的联系,通过高通量测序技术对健康和枯黄的圆柏针叶进行了分析。研究结果显示:6组样品测序共得到2,338,753条有效序列,683个操作分类单元(Operational Taxonomic Units,OTUs)。ACE、Chao1、Shannon指数表明发病组样品的物种丰富度与多样性略高于健康组。门分类水平上,两组样品的优势菌群均为子囊菌门,在属分类水平上,枝孢属Cladosporium是健康组样品中的优势属,球腔菌属Mycosphaerella是发病组样品中的优势属。在群落结构组成上,健康组样品中枝孢属Cladosporium、球腔菌属Mycosphaerella、丝状担子菌属Filobasidium相对丰度均高于发病组,组成占比也较为均匀,发病组样品中除Mycosphaerella之外其余属真菌占比均较低,没有明显的层次结构。Beta多样性显示6组样品大致分为两个分布区,各样品组间差异较小,两组样品差异较为明显。属分类水平上大多数属间呈正相关,负相关主要集中球腔菌属Mycosphaerella、Zymoseptoria、Rachicladosporium等属,这几个属在发病组中的丰度均高于健康组样品。

To understand the structure and diversity of the endophytic fungal community in needles of Juniperus przewalskii in the northwest arid region and to explore the association between endophytic fungi and the growth status of Juniperus przewalskii,healthy and yellowed cypress needles were analyzed by high-throughput sequencing technology.The results showed that 2,338,753 valid sequences with 683 operational taxonomic units(OTUs)were sequenced from 6 groups of samples.ACE,Chao1,and Shannon indices indicated that the species richness and diversity of samples in the morbidity group were slightly higher than those in the healthy group.At the phylum level,the dominant phylum in both groups was Cysticercus,and at the genus classification level,Cladosporium was the dominant genus in the healthy groups and Mycosphaerella was the dominant genus in the morbid groups.In terms of community structure composition,the relative abundance of Cladosporium,Mycosphaerella,and Filobasidium were higher in the healthy groups than in the morbid groups,and their composition was more uniform,while the proportions of the other genera in the morbid groups were lower except for Mycosphaerella,and there was no obvious hierarchical structure.Bata diversity showed that the six groups were roughly divided into two distribution areas,and the differences between the groups were small,and the differences between the morbid and healthy groups were more obvious.Most genus were positively correlated,and negative correlations were mainly concentrated in the genera of Mycosphaerella,Zymoseptoria,and Rachicladosporium,which were all more abundant in the morbidity groups than in the healthy groups.