ITS barcoding-based species identification for Sanghuangporus (Basidiomycota), a genus of medicinal mushrooms

Abstract

“Sanghuang” is a kind of important medicinal mushrooms and taxonomically represented by members in the fungal genus Sanghuangporus. Species of Sanghuangporus referred to medicinal studies and industry are discriminated mainly by BLAST search of GenBank with ITS barcoding region as a query. However, the inappropriately labeled ITS sequences related to “Sanghuang” in GenBank restrict accurate species identification and, to some extent, the utilization of these medicinal resources. Here, we examined all available 271 ITS sequences related to “Sanghuang” from GenBank including 31 newly submitted sequences for this study. Of these sequences, more than half were mislabeled and the corresponding species names are corrected. The mislabeled sequences mainly came from strains by non-taxonomists. Based on the analyses of ITS sequences submitted by taxonomists, we treat Sanghuangporus toxicodendri as a later synonym of S. quercicola, and the intraspecific and interspecific differences are below 1.50% (but S. weirianus) and above 1.50%, respectively. Moreover, ten potential diagnostic sequences are provided for hyperbranched rolling circle amplification to rapidly detect three common commercial species, viz. S. baumii, S. sanghuang and S. vaninii. Generally, the current results provide a practical method for ITS barcoding-based species identification of Sanghuangporus, and will promote medicinal studies and industrial development from the taxonomic perspective.