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目的:建立用rDNA序列分析对食用菌的菌种进行快速分类鉴定的分子技术方法。方法:对香菇、草菇、平菇等十五种常见栽培食用菌的30个菌株的18S rDNA及ITS序列进行测序分析,用NJ(neighbor-joining)法构建系统发育树。结果:由18S rDNA序列构建的系统发育树表明:常见栽培食用菌菌种的门间相似性≥94.2%,纲间相似性≥98.3%,目间相似性≥98.5%,科、属、种间的相似性都极高,在发育树图上亲缘关系近的属种会聚在同一分支。由ITS序列构建的系统发育树表明:常见栽培食用菌菌种的ITS序列在科、属、种水平上的聚类可信度高且易于鉴定区分,侧耳科内香菇属和侧耳属相似性为88%;蛹虫草和冬虫夏草相似性为91%;侧耳属内种间相似性≥99.5%,可信度为99%;香菇种内相似性接近100%,但仍存在细微的碱基差异。结论:本研究首次将18S rDNA和ITS两个目标片段结合分析,对常见栽培食用菌的进化关系进行研究,结果表明rDNA序列分析在食用菌的菌种分类鉴定上是一种快捷有效的方法。
OBJECTIVE: To establish a molecular method for the rapid classification of edible fungus strains by rDNA sequence analysis. Methods: The 18S rDNA and ITS sequences of 30 isolates of fifteen commonly cultivated edible fungi, such as mushrooms, straw mushrooms and flat mushrooms, were sequenced and analyzed. The phylogenetic tree was constructed by NJ (neighbor-joining) method. Results: The phylogenetic tree constructed by 18S rDNA sequence showed that the similarity of door to common edible fungus strains was ≥94.2%, the similarity between the two sides was ≥98.3%, the similarity between eyes was ≥98.5% The similarity is very high, in the development of tree map near the genus converge in the same branch. The phylogenetic tree constructed by ITS sequences showed that the ITS sequences of common cultivated edible fungi strains were highly reliable and easy to identify and distinguish among the families, genera and species. The similarity of the genus Leptosphaeria and Pleurotus in Pleurotus 88%; Cordyceps militaris and Cordyceps sinensis 91% similarity; Pleurotus species similarity between ≥ 99.5%, the credibility of 99%; similar within the mushroom species close to 100%, but there are still subtle differences in base. Conclusion: This study, for the first time, combines 18S rDNA and ITS target segments to study the evolutionary relationship of common cultivated edible fungi. The results show that rDNA sequence analysis is a quick and effective method for the classification and identification of edible fungus strains.