Phylogeny And Taxonomy Of Archilejeunea (Lejeuneaceae,Marchantiophyta) Based On Molecular Markers And Morphology

Archilejeunea(Spruce)Steph.,belonging to Lejeuneaceae subfam.Ptychanthoideae,with about 27 species,is pantropical in distribution.The Archilejeunea species are traditionally placed in two subgenera,subg.Archilejeunea and subg,Dibrachiella.Archilejeunea subg.Archilejeunea is very similar to Verdoornianthus,while Archilejeunea subg.Dibrachiella is closely related to Spruceanthus.Recent molecular phylogenetic analyses suggested that the genera of Ptychanthoideae are monophyletic with the exception of Archilejeunea.Besides,the treatments of the African and Asiatic species of Archilejeunea are incomplete or outdated and several species have not been studied since their first publication.As a result,the revision of the genus is necessary.In the present study,a systematic investigation of the genus Archilejeunea was carried out based on morphological-anatomical and molecular phylogenetic analyses of the worldwide samples.The morphological-anatomical investigation was based on 600 specimens of Archilejeunea and 400 Spruceanthus and five Verdoornianthus,including 47 type specimens.For the molecular analysis we sampled 46 species(74 accessions)in 17 genera of Ptychanthoideae,including 12 species(29 accessions)of Archilejeunea,five species of Spruceanthus and both species of Verdoornianthus.For the outgroup we included eight species(9 accessions)representing six genera of Lejeuneoideae tribe Brachiolejeuneeae.Two chloroplast regions(rbcL,trnL-F)and nuclear ribosomal internal transcribed spacers 1 and 2 with the intervening 5.8S ribosomal subunit(nrITS)were used for maximum parsimony(MP),maximum likelihood(ML)and Bayesian inference(BI)phylogenetic analyses.The results are as follows:1.Traditionally defined Archilejeunea is not monophyletic.The newly defined genus Archilejeunea s.str.agrees with A.subg.Archilejeunea,while A.subg.Dibrachiella is raised to the generic level.Archilejeunea s.str.is separated from Dibrachiella stst.nov.by the pycnolejeuneoid innovations of gynoecia and never reduced leaf lobules.2.Archilejeunea s.str.contains the five species and one subspecies from tropical America,and a new species,Archilejeunea gradsteinii X.Q.Shi&R.L.Zhu,is firstly described in West Africa.The sister relationship of Archilejeunea and Verdoornianthus is strongly supported.3.The genus Dibrachiella contains nine species,and the diagnostic characters are the:1)Lejeunea-type branching,2)epidermal cells similar to or more larger than medullary ones,without subepidermis,3)entire leaves,underleaves and bracts,4)isodiametric cells with small,usually simple-triangular trigones and segmented oil bodies,5)often reduced leaf lobules and rather small,6)distant to subimbricate underleaves,7)autoicous sexuality,8)gynoecia with a single or paired,lejeuneoid innovations,and 9)perianths with 4-5 keels.The genus widely spreads in tropical America and Africa.Spruceanthus is morphologically very similar to Dibrachiella,and differs from the latter in the homogeneous oil bodies,often presence of microphyllous branches and 5-12-keeled perianths.4.Five species previously placed in Archilejeunea,namely A.abbreviata,A.amakawana,A.kiushiana,A.olivacea and A.planiuscula,are resolved in Spruceanthus based on morphological-anatomical and molecular analyses.Furthermore,Archilejeunea planifolia,A.brachyatha and A.incrassata was transfered to Spruceanthus based on morphological characters.The number of Spruceanthus is raised 16 species,and the genus is pantropical in distribution.5.Archilejeunea nobilis is transferred to Marchesinia as M.nobilis based on morphological traits.It is an older name for Marchesinia madagassa.As a result,one new genus,18 new combinations and six new synonyms are proposed:Dibrachiella(Spruce)X.Q.Shi,R.L.Zhu&Gradst.,stat.nov.? Lejeunea subg.Archilejeunea Spruce sect.Dibrachiella Spruce,Trans.&Proc.Bot.Soc.Edinburgh 15:90.1884?Archilejeunea subg.Dibrachiella(Spruce)Schiffn.in Engler&Prantl,Nat.Pflanzenfam.1,3:130.1893.Type:Dibrachiella auberiana(Mont.)X.Q.Shi,R.L.Zhu&Gradst.(?Lejeunea auberiana Mont.).Dibrachiella africana(Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella alata(Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella auberiana(Mont.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella autoica(Vanden Berghen)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella bischleriana(Gradst.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella brevilobula(Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.=Archilejeunea helenae Pocs&Gyarmati,Cryptog.,Bryol.27:104.2006,syn.nov.Dibrachiella jonesii(Vanden Berghen)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Dibrachiella elobulata(Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.=Archilejeunea linguifolia Steph.,Sp.Hepat.4:708.1911,syn.nov.Dibrachiellaparviflora(Nees)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus abbreviatus(Mitt.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.=Archilejeunea mauritiana Steph.,Hedwigia 34:60.1895,syn.nov.Spruceanthus amakawanus(Inoue)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus brachyanthus(J.B.Jack&Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus incrassatus(Steph.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus kiushianus(Horik.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus olivaceus(Hook.f.&Taylor)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthusplanifolius(Horik.)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.Spruceanthus planiusculus(Mitt.)X.Q.Shi?R.L.Zhu&Gradst.,comb.nov.=Archilejeunea apiculifolia Steph.,Sp.Hepat.6:558.1924,syn.nov.=Archilejeunea falcifolia Steph.,Akad.Wiss.Wien,Math.-Naturwiss.Kl.,Denkschr.85:196.1910,syn.nov.Marchesinia nobilis(Gottsche)X.Q.Shi,R.L.Zhu&Gradst.,comb.nov.=Marchesinia madagassa Steph.,Sp.Hepat.5:144.1912,syn.nov.The present study determined the phylogenetic relationships of the species of the polyphyletic Archilejeunea.The phylogenetic relationships between Archilejeunea vs.Verdoornianthus,and Dibrachiella vs.Spruceanthus were resolved.The results provide valuable information for further revisions of the genera Dibrachiella and Spruceanthus.