Taxonomy And Molecluar Phylogeny Of The Genus Clavariadelphus In China

Clavariadelphus Donk is a genus of clavarioid fungi that belongs to Clavariadelphaceae(Gomphales,Agaricomycetes,Basidiomycota),This genus have clavate,ligulate,or turbinate basidiocarps,soft in texture when fresh,basidiospore ovate,ellipsoid to long ellipsoid,basidia clavate,with 4 sterigmata,clamp connection present;Up to now,19 species have been reported and are widely distributed in temperate regions of the North Heimsphere.Six species were previously recorded in China:Clavariadelphus ligula,C.mirus,C.pistillaris,C.sachalinensis,C. truncates and C.yunnanensis.At present,the study of morphology and molecular systematics of Clavariadelphus in China has not paid enough attention,and the abundant resources of this genus in China have been neglected.Therefore,the taxonomy and molecular systematics of specimens collected from different regions of China were studied in this paper to increase the knowledge of the species diversity of Clavariadelphus.A total of 15 species of Clavariadelphus have been identified in this study,of which four new species have been identified and will be published:C.aurantiacus,C.micronatus,C.psedoelongatus and C. tenuis.In this paper,the macroscopic and microscopic morphology and habitat characteristics of each new species were described in detail,and the existing species were supplementary described.An indentification key of this genus is provided.In this study,five gene fragments(ITS,nr LSU,RPB2,EF1 and ATP6)were used to study the molecular phylogeny of the genus.The phylogenetic trees were constructed by combining Bayesian and Maximum likelihood methods,the results show that,the species differentiation of ITS,ATP6 and EF1 were more effective.Compared with the combined analysis of five genes,ITS+ATP6+EF1 was more suitable for the interspecific analysis of Clavariadelphus due to the disruptive effect of RPB2 gene fragment.The ITS sequence was also used to study the relationship between Clavariadelphus and related genera,and it was found that this genus is a polyphyletic group,it is closely related to Lentaria,Ramaria and Gomphus.In this study,two chemical reagents,5%KOH and 10%FeCl₃,were used to study the chemical color reaction of Clavariadelphus.The results showed that KOH solution was more suitable than FeCl₃solution to distinguish the interspecific relationships of this genus.