Taxonomy Of Edible Species Of Russula In Yunnan

Russula,type genus of Russulaceae,is the biggest genus of the family.Species of the genus are widely distributed from the tropics to cold climatic zones,and form ectomycorrhizae with with various plants,including Betulaceae,Fabaceae,Fagaceae,Junglandaceae,Pinaceae and Myrtaceae.Many species of Russula have gourmet and medicinal value,some toxic and a few deadly poisonous.Russulas are one of the most dominant groups commercialized in Yunnan markets.Accurate recognition of Russula species in Yunnan is of great significance for food safety.From 2017 to 2018,422 Russula specimens were collected in the counties of Jingdong,Luquan,Maguan,Nanhua and Wenshan,Yunnan Province,among which 68 specimens were collected from markets.To delimit species,morphology was studied using modern taxonomic method of agarics and the fungal bar-code internal transcribed spacer of ribosomal DNA(ITS)was analyzed using Neighbor-Joining method.Three loci,D1?D2 domains of nuc 28 S rDNA(28S),part of the second largest subunit of the RNA polymerase II(rpb2)(6–7 region)and translation elongation factor 1-alpha(tef1)were analyzed using Maximum Liklihood and Bayesian Inference to infer the phylogenetic positions of the representative species.A total of 30 species were identified,among which 12 were sold on markets and six of the other 18 species are edible.Nine species are new to science: i.e.R.atrorubra,R.dahongjun,R.griseonigricans,R.huotanjun,R.lilaceoxantha,R.maguanensis,R.rubrimaginata,R.sinopeckii and R.substriata,five new to China,i.e.R.aureorubra,R.compactoides,R.dhakuriana,R.kewzingensis and R.pseudocompacta.These species belong to four subgenera,i.e.Subg.Compactae,Subg.Heterophyllidia,Subg.Malodora and Subg.Russula.A key for recognizing subgenera and species is given.Detailed morphological descriptions,color photos of fruiting bodies,Scanning-Electronic-Microscopy photos of basidiospores and line drawings of microscopical characters are provided for each species.ITS sequences and morphological characters suggest that a large number of Russula species in Yunnan are potential new taxa.The real diversity of this group needs further investigating.