Taxonomy And Phylogeny Of Postia And Related Genera In China

Postia,as an important fungal genus,is very rich in species diversity and has a wide distribution.Oligoporus and Spongiporus are often regarded as synonyms of Postia,Osteina and Rhodonia are respectively independent of Postia as autogenus.With the increasing species,the definitions of Postia and related genera are indistinct,and the genetic relationships among species are unclear.However,the comprehensive phylogeny of Postia has not been analyzed,and the taxonomy on the Chinese species of Postia is mainly based on morphological characteristics.In this study,552 specimens belonging to 48 species of Postia and related genera are identified,DNA of 48 species and multiple gene sequences of 370 samples are successfully obtained.In the course,four new genera were established,13 new species were discovered,and 20 combinations were proposed.The Bayesian,Maximum Parsimony and Maximum Likelihood analyses inferred from the combined datasets of ITS-nLSU-RPB2 sequences and ITS-nLSU-mtSSU-nSSU-RPB1-RPB2-TEF1 sequences indicated that Postia and related genera were embedded in the antrodia clade and formed different lineages.Phylogeny demonstrats 10 major lineages,in addition to Postia s.s.and the removed individual branches of Osteina and Rhodonia,the four lineages separated from Postia s.s.were established as new genera:Amaropostia,Calcipostia,Cystidiopostia and Fuscopostia,the other three lineages were identified as Cyanosporus,Oligoporus and Spongiporus.According to the above phylogenetic analyses and morphological characteristics,some of the so-called species of Postia were transferred to Osteina,Rhodonia,Cyanosporus,Spongiporus and the four new genera,but some are still addressed in Postia s.l.Combined morphology and phylogeny,the conclusions are as follows:1.The texture and taste of fruiting body,the shape of basidiospores,thin or thick walled and whether cyanophilous are important taxonomy features at generic level.The growth habit,the features of basidiocarps(the shape,color,taste,texture etc.),the pileal surface(zonate,glabrous,tomentose,pubescent,velutinous,hirsute),the size and shape of pores,the texture and thickness of context and tubes,the characteristic of cystidia,cystidioles and basidiospores(shape and size)are important taxonomy features at species level.2.Postia s.s.differs from other genera by soft and corky fruiting body when fresh,corky to fragile when dry,thin-walled and allantoid basidiospores,and gelatinous hyphae occasionally present;Oligoporus is distinguished from Postia s.s.for taxa having resupinate and gossypine basidiocarps when fresh,thick-walled and cyanophilous basidiospores,and chlamydospores frequently present;imbricate basidiospores with zonated pileal surface and hyphal pegs occasionally presenting could differentiate Spongiporus from Postia s.s.;Cyanosporus has blue tint basidiocarps,and weakly cyanophilous basidiospores,which clearly different from other genera;Bone hard basidiocarps and undulate pileal margin are distinguishing features of Osteina and others;Rhodonia differs from Postia s.s.by its fairly large,thick resupinate basidiocarps and big cylindrical basidiospores;New genus Amaropostia differs from Postia s.s.by woody hard basidiocarps when dry,and bitter taste;Calcipostia has large,occasionally substipitate,calcareous basidiocarps,pileal surface with circular guttulate depressions;Cystidiopostia is easily distinguished by resupinate basidiocarps and apically encrusted cystidia in hymenium;Fuscopostia differs from other genera by relatively thick fruiting body and turning to brownish pileal surface and pore surface when bruised.