Systematics Of Coltricia And Coltriciella In China

Coltricia Gray and the related genus Coltriciella Murrill are a cosmopolitan group of Hymenochaetacea.Some species in this group are terrestrial and form mycorrhiza with plant roots.These ectomycorrhizal species paly important roles in the cycle of carbon and nitrogen in ecosystems.There are also some species in Coltricia and Coltriciella associating with strongly decayed wood and causing a white rot with laccase.These laccase-producing species suggest their potential for industrial applications.It is difficult to distinguish these two genera because of the complex habitate,mini fruting bodies and exceedingly closed morphology characteristics.Misidentification and being confounded while producing and applicating could not be ameliorated with the recent morphology and molecular evidences.Therefore,taxonomic and phylogenetic studies of genera Coltricia and Coltriciella in China are carried out.In the morphology studies,the macro-and micro-morphological descriptions,habitate,distribution in China and illustration drawings of 21 species in Coltricia and 9 species in Coltriciella are provided with identification keys.The main morphology conclusions are as follows:the micro-morphological characters of Coltricia and Coltriciella are simple and lack of unique features,so the diameter and patterns of hyphae,the size and shape of basidiospores are important characters for species identification.But the basidiospores size of some species may be wide-ranging.The macro-morphological characters,especialy the shape of fruiting bodies,stipe patterns,features of pileal surfaces,thickness of margins and color of pores paly a significant role in identification.So,maintaining complete while specimens collecting and depositing is very important in case of the fragile fruiting bodies.Coltriciella differs from Coltricia mainly by the ornamented basidiospores,while other features especially centrally stipitate fruiting bodies and terrestrial species are shared by these two genera.The phylogenetic analyses are based on the internal transcribed spacer(ITS)regions,the nuclear large subunit(nLSU)ribosomal RNA gene rigions,the nuclear small subunit(nSSU)ribosomal RNA gene rigions,the mitochondrial small subunit(mtSSU)ribosomal RNA gene rigions,the translation elongation factor 1-a(tefl)gene rigions,the RNA polymerase II second-largest subunit 1 gene(rpb1)rigions and the RNA polymerase II second-largest subunit 2 gene(rpb2)rigions.The phylogenetic trees are constructed with Maximum Likelihood(ML),Maximum Parsimony(MP)and Bayesian Inference(BI)analyses.The main phylogenetic conclusions are as follows:These genera Coltricia and Coltriciella form a well-supported lineage,which is distint from other genera in Hymenochaetacea.Coltriciella clusters within Coltricia,and there is no obvious scircumscription between these two genera.The terrestrial species and wood-inhabiting species disperse and do not cluster together,respectively,and the scircumscription of some species may also be vague.The PCR application parameters of ITS are approved,but ITS sequences are highly divergent and poorly alignable among closely related species.Rpbl,rpb2 and tef1 are the most suitable gene loci.According to the conclusions of taxonomic and phylogenetic studies,maybe the genus Coltriciella ought to be regarded as a group,which has special basidiospores features,within Coltricia instead of being an independent genus based on recent morphology and molecular evidences.In the present study,seven new species in Coltricia and Coltriciella were reported:Coltricia austrosinensis,C.lateralis,C.minima,C.rigida,C.wenshanensis,Coltriciella globose and C.pseudodependens.Two species were reported new to China:Coltricia velutina and Coltriciella pusilla?...