青藏高原黄绿蜜环菌纯培养菌种的分离培养及分子鉴定

首次从采自青藏高原、与高原牧草嵩草属Kobresia草本植物形成外生菌根的黄绿蜜环菌Armillarialuteo-virens子实体中分离获得一组织分离菌株,运用rDNA-ITS和rDNA-IGS-1测序技术对该组织分离菌株是否为黄绿蜜环菌的纯培养菌种进行分子鉴定,并基于黄绿蜜环菌的5.8S/ITS和IGS-1序列进行核酸序列数据库GenBank同源性检索比对、构建系统发育树。结果表明,本研究获得的黄绿蜜环菌子实体组织分离菌株即为其纯培养菌种。基于ITS的系统发育分析表明黄绿蜜环菌与口蘑科内其它属间物种的系统发育关系较远;基于IGS-1的系统发育分析表明黄绿蜜环菌与蜜环菌属内的其它种序列差异较大,系统发育关系较远,而与Lepiota属内的部分种具有较近的系统发育关系。本研究首次基于分子手段对我国青藏高原的黄绿蜜环菌种进行了分离培养、分子鉴定和系统发育分析,为黄绿蜜环菌的科学分类提供了分子依据。

Pure culture isolation, cultivation and molecular identification of Armillaria luteo-virens from Tibet Plateau

Armillaria luteo-virens is a ectomycorrhizal fungus symbiotic with some species of Kobresia in Tibet Plateau, China. A strain was recently isolated from fruitbody tissue of the fungus. To determine whether the strain is the pure culture of the fungus, the internal transcribed spacer (ITS) region and the first intergenic spacer region (IGS-1) of the nuclear ribosomal DNA of fruiting body and the isolated strain were sequenced and compared. Further, the 5.8S/ITS and IGS-1 sequences of the species were BLAST matched with GenBank database on homology and a phylogenetic tree was constructed based on 5.8S/ITS sequence and two phylogenetic trees were constructed separately based on two IGS-1 sequences. The results demonstrated that the strain isolated from fruitbody tissue of Armillaria luteo-virens was the true pure culture of the fungus. Phylogenetic analysis based on 5.8S/ITS sequence indicated Armillaria luteo-virens has a distant phylogenetic relationship with other genera of Tricholomataceae. Phylogenetic analysis based on two IGS-1 sequences indicated there were significant differences between the IGS-1 sequence of Armillaria luteo-virens and that of other species of Armillaria. Armillaria luteo-virens has a relatively close phylogenetic relationship with some species of Lepiota.