The Species Resources Of Hygrophorus In Parts Of China

Objectives:Hygrophorus(Hygrophoraceae,Agaricales)has glutinous pileus and is widely distributed around the world.Most species are edible,and have medicinal and ecological values,such as anti-HIV,anti-cancer,antibacterial,antioxidant,and other activities.The taxonomic study of this genus is more in-depth in Europe and North America,but less thoroughly documented in China.This study surveys the resource of Hygrophorus in China,and establishes a natural classification framework of the genus,laying a foundation for the further development and utilization of the genus.Methods:Phylogeny,microchemical reactions,ultrastructure,isotope analysis,and taxonomy were used.The phylogenetic study included DNA extraction,amplification,and sequencing of ITS,nrLSU,and tef1-α.Microchemical reactions were conducted using seven chemical reagents[10%(weight/volume)phenol,95%(volume/volume)ethanol,10%(w/v)ferric chloride,10%(w/v)ferrous sulfate,5%(w/v)potassium hydroxide,Melzer’s reagent,10%(w/v)ammonium hydroxide].The ultrastructure study was to scan and photograph basidiospores and mycelial hyphae.Isotope analysis was to measure the amount of 13C and 15N isotopes of basidiomata.Taxonomy included macro-morphological descriptions,micro-morphological characters,and combined with geographical information and ecological habitat.Results:Six hundred and forty-nine sequences,including 276 sequences of ITS,246 sequences of nrLSU,and 127 sequences of tef1-α,were obtained from 440 specimens(409 from China,31 from Germany,Spain,Sweden,United Kingdom,and the USA).Fifty-seven taxa were identified,belonging to H.sect.Aurei,H.sect.Chrysodontes,H.sect.Hygrophorus,H.sect.Olivaceoumbrini s.l.,and H.sect.Pudorini,respectively.Among them,22 taxa were new to science,e.g.,H.alpinus,H.atrofuscus,H.atropurpureus,H.aurantioceps,H.aurantiophyllus,H.aurantiosquamosus,H.brunneiceps,H.cortinarius,H.esculentus,H.griseolus,H.habaensis,H.luteolus,H.ochraceodiscus,H.orientalis,H.parvirussula,H.paulus,H.pseudohypothejus,H.qinggangjun,H.rufescens,H.shennongjiaensis,H.xiangjun and H.yunnanensis;four taxa were new to China,e.g.,H.abieticola,H.agathosmoides,H.pinophilus and H.yukishiro;21 taxa were previously described species,e.g.,H.agathosmus,H.annulatus,H.arbustivus,H.chrysodon,H.deliciosus,H.erubescens,H.fuscopapillatus,H.gliocyclus,H.glutiniceps,H.glutinifer,H.griseodiscus,H.hedrychii,H.hypothejus,H.korhonenii,H.lucorum,H.penarioides,H.pudorinus,H.queletii,H.russula,H.secretanii and H.speciosus;nine taxa were new phylogenetic species.In addition,H.robustus had been combined into Tricholoma.Molecular phylogenetic and morphology studies had been carried out on 41 taxa.The species diversity and biogeography of each section were discussed.Conclusions:There are currently 50 taxa in China,including 29 taxa which are originally described from China,ten known species from Europe or North America,two Asian species,and nine unknown species.A known one,H.robustus,is confirmed to belong to Tricholoma.The results indicate that Hygrophorus is abundant in China.Most taxa have strict geographical distributions;minority species are widely distributed,including five Eurasian species(H.gliocyclus,H.hedrychii,H.lucorum,H.pinophilus,and H.queletii),six European-North American species(H.exiguous,H.olivaceoalbus,H.piceae,H.pustulatus,H.secretanii,and H.suaveolens),and five Holarctic species(H.abieticola,H.agathosmoides,H.erubescens,H.pudorinus,and H.speciosus).Up to now,there are at least thirteen sections within Hygrophorus;the species in sect.Aurei,sect.Nudolidi,sect.Olivaceoumbrini s.s.and sect.Tephroleuci prefer coniferous forests;the most species in sect.Fuscocinerei,sect.Limacini,sect.Hygrophorus and sect.Pudorini are associated with broadleaf trees.