一株祁连野生羊肚菌多基因联合分子鉴定及其生物地理分析

Taxonomic identification and biogeographic analysis of a wild strain of Morchella in Qilian based on multiple genes

摘要:

【背景】青海野生羊肚菌野生资源丰富，但物种识别度低，相关研究滞后。【目的】鉴定识别采集自青海祁连的野生羊肚菌并分析其生物地理。【方法】利用形态学、多基因谱系一致性系统发育学物种识别法与多基因分子系统学相结合的方法，鉴定野生羊肚菌并分析该物种分化时间和重建祖先区域。【结果】野生羊肚菌菌株MQL-1子实体菌盖呈黄褐色，圆顶，菌柄呈白色、中空，形似羊肚菌，孢子大小为（21.17±4.33）μm×（14.26±3.25）μm，菌丝直径（13.95±3.19）μm。系统发育分析结果表明分离到的菌株MQL-1与羊肚菌属中的黄色羊肚菌类群的内转录间隔区（internal transcribed spacer，ITS）序列相似性高达99%，多基因谱系一致性系统发育学物种识别法将MQL-1识别为粗柄羊肚菌（Morchella crassipes）。分化时间估算和祖先重建结果表明青海祁连粗柄羊肚菌MQL-1与云南M.crassipes M10的分化时间12.75 Mya （百万年前），其重建的最可能的祖先区域为印度（52.49%）。【结论】本研究得到了一株青海祁连地区粗柄羊肚菌菌株并确定了其正确的科学命名，丰富了青海省羊肚菌资源信息数据库，为后续的工作奠定了基础，也为真菌研究提供新思路。

Abstract:

[Background] Qinghai harbors rich wild Morchella resources, whereas studies remain to be carried out for the species identification and characterization. [Objective] To identify a wild Morchella strain collected from Qilian, Qinghai and analyze its biogeography. [Methods] The morphological characteristics were combined with genealogical concordance phylogenetic species recognition and the phylogenetic analyses to identify the Morchella strain. Furthermore, species divergence time was analyzed and the geographic ancestral region was rebuilt. [Results] The strain MQL-1 presented a yellow-brown domed cap and a white hollow stalk, with a spore size of (21.17±4.33) μm×(14.26±3.25) μm and a hyphal diameter of (13.95±3.19) μm. Strain MQL-1 had 99% ITS sequence identity with Esculenta clade of the genus Morchella, and the genealogical concordance phylogenetic species recognition identified MQL-1 as Morchella crassipes. The estimated divergence time and reconstructed geographic ancestral region indicated that M. crassipes MQL-1 diverged from M. crassipes M10 at approximately 12.75 Mya (million years ago), and its most likely reconstructed geographic ancestral region was India (52.49%). [Conclusion] We isolated and identified a wild Morchella strain in Qinghai. This study enriched the information database of Morchella resources in Qinghai, laid a foundation for the follow-up work, and provided new ideas for fungal research.