Taxonomy,Phylogeny And Divergence Time Of Porodaedalea

The genus Porodaedalea belongs to one of the important wood-decaying fungi distributed in the boreal-temperate forests.Members of the genus are pathogenic on gymnosperm trees,causing a white pocket rot.In addition,many species in the genus have valuable medicinal functions.In this study,255 specimens from Europe,North America,North Africa,and Asia were studied.For morphological examination,macroscopic morphology and microstructure were observed,and basic data of each important element were measured,species identification is based on these data combined with the host and distribution of each species.Phylogenetic analyses were performed with partial sequences from four loci(ITS,nLSU,EF1-? and RPB2)using Maximum parsimony(MP)and Bayesian inference(BI)for the phylogenetic relationships among species,the BEAST v1.8.0 package was used to infer the divergence time of Porodaedalea.The result of phylogenetic analyses shows that 16 terminal clades are strongly supported within Porodaedalea.Based on morphological evidences,six new species,Porodaedalea alpicola S.J.Dai&Y.C.Dai,P.chinensis S.J.Dai&F.Wu,P.indica Spirin&Vlasak,P.kesiyae S.J.Dai&Y.C.Dai,P.microspora S.J.Dai&Y.C.Dai and P.yunnanensis S.J.Dai&Y.C.Dai,are described and illustrated.The illustrated description of species of Porodaedalea are given,and a key to so far known species in Porodaedalea is proposed.Based on studied samples from North Hemisphere,the main morphological characteristics of Porodaedalea as summarized:basidiocarps perennial,solitary to imbricate,pileate or effused-reflexed to pileate,pore surface slightly glancing;a dimitic hyphal structure with generative hyphae with simple septa,setae abundant,mostly originating from subhymenium,sometimes embedded in trama,not seen at dissepiment edges,subulate,dark brown,thick-walled,cystidioles present or absent,basidia clavate,basidioles shorter than basidia,basidiospores hyaline,thin-to slightly thick-walled,smooth,usually glued in tetrads or more,moderately cyanophilous.The biogeopraphic analysis showed that divergence time of Hymenochaetales was 184.22 ± 1.46 Mya(131.51-241.41,95%HPD)and Porodaedalea was 7.84 ± 1.71 Mya(4.71-11.21,95%HPD)during the late Miocene.Furthermore,we found that the genus had a more distinctly regional endemism.