Taxonomy And Molecular Systematics Of Immersaria From China

Eight species of Immeraria belonging to Lecanoromycetes,Lecanoromycetidae,Lecideales,Lecideaceae were reported worldwide,four of which were reported from China.Among 25 genera of Lecideaceae,only Immersaria has both lecanorine and lecideine apotheciate,but little molecular data of this genus could clarified its monophyletic.Species of Lecideceae are widely distributed in China,but few records of Immersaria were reported.Before this study,only morphological researches of Immersaria have been done and the phylogeny studies are lacking.The author has collected 5343 lichen specimens in the duration of the master’s degree,140 of which were used for this study.To clarify the biodiversity of Immersaria in China,this study focus on the phylogenetic position of Immersaria in Lecideaceae,the taxonomic boundary and distribution of the genus and species by the morphological,anatomical,chemical and phylogenetical evidences based on 347 specimens from field work and the herbarium collections and 353 DNA sequences obtained from fresh materials.Experiments including observation,hand-cutting section,recording of characters,the spot test of cortex and medulla,identified of lichen secondary metabolite by TLC and molecular experiments like DNA extraction and PCR extension.And the results are as follows:1.The phylogenetic analyses of the family LecideaceaeThe 5-loci phylogenetic tree(ITS,nr LSU,RPB1,RPB2 and mt SSU)of Lecideaceae clearly showed that Immersaria split as two clades(clade 1 and clade 2),in which clade 1 including all the lecideine apothecia species and clade 2 including all the lecanorine apothecia species.Clade 1 with type species of the genus,Immersaria athroocarpa,is regarded as true Immersaria and clade 2 is removed.Based on the mophology,anatomy,chemistry and phylogeny evidences,the revised concept of Immersaria is as follows: atrobrunnea-type thallus crustose;immersed lecideine apothecia with a reduced margin;brown areolae with an epinecral layer;brown or green epihymenium without plectenchyma developed on the top;Porpidia-type asci with halonate ascospores.Clade 2 with lecanorine apothecia species proposed as a new lecanorine genus Lecaimmeria C.M.Xie,Lu L.Zhang & Li S.Wang.The new genus Lecaimmeria has immersed lecanorine apothecia;red or dark brown,orange areolae with a epinecral layer;orange epihymenium with a distinct plectenchyma developed on the top;Porpidia-type asci with halonate ascospores.2.The phylogeny and taxonomy of the genus Immersaria and LecaimmeriaBased on taxonomy and phylogeny,the circumscription of Immersaria were revised and a new genus was proposed.Furthermore,4-loci tree(ITS,nr LSU,RPB1 and RPB2)of Immersaria and Lecaimmeria generated respectively showed 6 highly supported monophyly lineage of Immersaria and 10 of Lecaimmeria.Four new species,Immersaria aurantia C.M.Xie & Li S.Wang,I.ferruginea C.M.Xie & Li S.Wang,I.shangrilaensis C.M.Xie & Lu L.Zhang,I.venusta C.M.Xie & Xin Y.Wang,one suspected new species of Immersaria,seven new species,Lecaimmeria botryoides C.M.Xie & Li S.Wang,L.lygaea C.M.Xie & Lu L.Zhang,L.mongolica C.M.Xie & Lu L.Zhang,L.orbicularis C.M.Xie & Lu L.Zhang,L.qinghaiensis C.M.Xie & Li S.Wang,L.tibetica C.M.Xie & Xin Y.Wang,L.tuberculosa C.M.Xie & Xin Y.Wang,and three new combinations,L.cupreoatra(Nyl.)C.M.Xie,L.iranica(Valadb.,Sipman& Rambold)C.M.Xie,L.mehadiana(Calat.& Rambold)C.M.Xie,were proposed.Keys,the descriptions and comments of two genera and known species were provided.Based on the morphology,chemistry and phylogeny,the definition of Immersaria with 4new species proposed was revised and a new genus Lecaimmeria with 3 new combination and 7new species were proposed.This study clarified the phylogenetic position of Immersaria and Lecaimmeria in Lecideaceae and the species diversity and distribution of two genera in China,which provides the scientific data for the researches of Lecideaceae in China and the compilation of Chinese Lichen Flora.