川西高原昆虫病原真菌的多样性

Diversity of Entomopathogenic Fungi in Western Sichuan Plateau

【目的】探讨川西高原的昆虫病原真菌种类多样性及其分布特点,为昆虫病原真菌的开发利用及川西高原物种多样性的研究提供参考。【方法】以川西高原13个不同海拔区域土壤总DNA为研究材料,通过illumina HiSeq测序平台测序得到有效数据,分析土壤样品中真菌群落结构组成、昆虫病原真菌的种类及其与海拔梯度变化的相关性。【结果】1)在门分类水平上,子囊菌门与担子菌门在每个海拔样品中的共同占比超过69%,占绝对优势;从属水平分布来看,各样品间的差异显著,最优势属均有不同。2)在13个土壤样品中检测到的昆虫病原真菌分属于肉座菌目3个科的18个属,其中麦角菌科的优势属为绿僵菌属,虫草科的优势属为棒束孢属与虫草属,线虫草科的优势属在不同的样品中存在差异。3)虫草科的虫草属与棒束孢属的种类丰度在肉座菌目中的占比分别在4300与3700 m时达到2个顶峰。【结论】川西高原病原真菌种类丰富,在不同海拔其丰度存在差异。昆虫病原真菌主要集中于子囊菌门肉座菌目的3个科,其中虫草科的变化差异最为明显:虫草属集中在海拔3400~4300 m,而棒束孢集中在海拔3400~3700 m。说明在海拔3400~4300 m的范围内虫草菌科真菌相对丰度较高。

【Objective】The main objective of this study is to investigate the diversity and distribution of entomopathogenic fungi in the Western Sichuan Plateau.【Method】The soil total DNA,sampled from the samples of 13 different altitudes in the Western Sichuan Plateau,was sequenced by illumina HiSeq sequencing.The composition of fungi community,the species composition of entomopathogenic fungi and their correlation with altitudes were analyzed.【Result】1)At the Phylum level,Ascomycota and Bassiodiomycota together accounted for more than 69%of each altitude sample,which was absolutely dominant.At the Genus level,there were significant differences in the relative abundance of pathogenic fungi among the 13 altitudes,and the most dominant genera were different at each altitude.2)The entomopathogenic fungi detected in 13 soil samples belonged to 18 genera of three families of Hypocreales,among which the dominant species of Clavicipitaceae was Metarhizium,the dominant species of Cordyceps were Isaria and Cordyceps,and the dominant genus of Ophiocordycipitaceae differed in different samples.3)The ratio of Cordyceps and Isaria in the Hypocreales reached two peaks at 4300 m and 3700 m.【Conclusion】The diversity of pathogenic fungi is rich and varies at different altitudes in the Western Sichuan Plateau.The entomopathogenic fungi are mainly distributed in three families of Ascomycota Hypocreales,among which the abundance of Cordycipitaceae is significantly different in different altitudes.The abundance of Cordyceps is located at the altitudes of 3400 m to 4300 m,while the abundance of Isaria is located at 3400 m to 3700 m,indicating that the abundance of Cordycipitaceae is comparatively higher at the altitude range from 3400 m to 4300 m.