基于多基因分析对我国红曲霉属Monascus真菌的系统发育研究

红曲霉属Monascus具有重要的经济和生态价值,但对该属的物种识别和系统发育学研究有限。本研究首先对红曲霉属红色组内物种开展ITS和LSU序列的测定并综合分析,结合GenBank中相关物种序列及菌株的形态学特征,探讨红曲霉属的系统发育关系,鉴定出红色组3个种,弗罗里达组7个种。其次采用红曲霉色素表型控制基因簇部分基因pksKS序列进行分析,以期解决ITS和LSU等基因序列分析无法有效区分红色红曲与紫色红曲不同形态种的问题。通过分子克隆测序与直接测序结果的比较,以及对3个血红红曲菌株单核苷酸多态性的分析,解析了血红红曲种内遗传差异,首次在红曲霉属真菌中发现疑似红色红曲血红自然杂交种。最后综合ITS、LSU、pksKS序列和形态学分析的结果,统一了红曲霉属内物种的系统发育关系,确认红色组包括3个种：红色红曲M. ruber、紫色红曲M. purpureus、血红红曲M. sanguineus;发现3个变种：红色红曲发白变种M. ruber var. albidulus、紫色红曲橙色变种M. purpureus var. aurantiacus及紫色红曲火红色变种M. purpureus var. rutilus;弗罗里达组包括7个种：弗罗里达红曲M. floridanus、苍白红曲M. pallens、新月红曲M. lunisporas、阿根廷红曲M. argentinensis、累西腓红曲M. recifensis、黄色红曲M. flavipigmentosum、蜂蜜红曲M. mellicola。另外,发现1个疑似杂交种：红色红曲血红杂种M. ruber × sanguineus。结果表明,红曲霉属具有丰富的物种多样性,而且通过多基因和形态学分析可以将相近种区分开来。

Phylogenetic relationship of the genus Monascus in China based on multi-gene sequence analyses

The genus Monascus has important economic and ecological value. In order to explore the systematic relationships of the genus Monascus, ITS and LSU genes of section Rubri were sequenced and analyzed and compared with the related genes of the related species and strains in GenBank. Three species in section Rubri and seven species in section Floridani were finally identified. The beta-ketoacyl synthase (pksKS) gene sequence of the Monascus pigment control gene cluster was also used to solve the problem that partial gene sequence analyses could not distinguish clearly the different morphological species M. ruber and M. purpureus. By comparing the results of TA cloning and direct sequencing, the single nucleotide polymorphism (SNP) of three M. sanguineus strains were further analyzed, and the genetic diversities of intra-species were firstly understood. Based on the results of sequence analyses of ITS, LSU and pksKS, in combination with morphological comparison between the related species, the genus Monascus is grouped into two major sections: Rubri and Floridani. Three species (M. ruber, M. purpureus and M. sanguineus) and three varieties (M. ruber var. albidulus, M. purpureus var. aurantiacus and M. purpureus var. rutilus) were identified within the section Rubri. Seven species (M. Floridanus, M. pallens, M. lunisporas, M. argentinensis, M. recifensis, M. flavipigmentosum and M. mellicola) were identified within the section Floridani. In addition, one single suspected nothospecies (M. ruber × sanguineus) was also found within the section Rubri. The results of the current study showed high level of species diversity in the genus of Monascus and the systematic relationship within the genus could be distinguished by polygenic and morphological analyses.