Spore Morphology And Its Systematic Implication In Athyrium Sensu Lato(Athyriaceae)from China

Based on the specimens collected in Herbarium of Pteridophyta Yunnan University(PYU),spore morphology of 98 species,4 varieties,3 forma and 1 hybrid of Athyriaceae,including:81 species,4 varieties and 1 hybrid of the Athyrium(5 of which are cited in previous studies),11 species and 3 forma of the Cornopteris,4 species of the Anisocampium,1 species of the Pseudathyium and Athyrium skinneri(Cite in previous studies),were studied under scanning electro microscope(SEM).The spore SEM observations correspond to the existing phylogenetic trees based on the combined data of 7 cpDNA sequences,namely:4 gene regions(atpA,atpB,matK and rbcL)and 3 intergenic spacer(rpL32-trnP IGS,rps4-trnS IGS and trnL-trnF IGS),the phylogenetic analysis of the spore morphology of the Athyrium,Three major perispore characters,including perine ornamentation,perine fold type and perine surface subtle ornamentation,were analyzed to investigate spore morphology evolution.The morphology of the perispore and its character state changes are described and discussed in a phylogenetic context.Based on the results of comprehensive molecular systematics and palynology,the specific findings are as follows:1.The spores of the Athyrium were bilaterally symmetric,ellipsoidal in polar view,bean-shaped or semiorbicular in equatoral view.Monolete,the laesura length varies from different species,the laesura was 1/2,1/3,3/4 of the equatorial axis or as long the equatorial axis.The spore size of the Athyrium was about 16.42?42.89(25.83)×26.28?61.33(39.81)?m.2.The spore ornamentation of the Athyrium was put into 7 categories:lophate folds,reticulate folds,extervermiculate,ornate,rugate and tuberculate.3.Based on the phylogenetic tree constructed by 7 cpDNA sequences,the topological structure of the phylogenetic tree obtained by the two methods of maximum parsimony method(ML)and Bayesian method(BI)was consistent,and the topology was in accordance with the results of Wei et al.(2017b),except that Athyrium skinneri doesn,t form a clade with the Anisocampium,but together with the Anisocampium,Cornopteris,Pseudathyrium and Athyrium were recovered to be monophyletic(ML BS=100;BI PP=1.00).The results showed that all the branches were well supported(ML BS?80%,BI PP>0.90)except for A.sect.Athyrium(ML BS=61%,BI PP=0.91).4.Spore morphological characteristics combined with molecular phylogenetic results,ancestral characters state reconstruction,the results show:Ani.s'ocampium was monophyletic(ML BS = 100%,BI[PP = 1.00),which was based on molecular phylogeny and spore morphology to support the Anisocampium separate from the Athyrium.Cornopteris and Pseudathyrium alpestre form a sister group(ML BS = 100%,BI PP= 1.00),which was based on molecular phylogeny and spore morphology to support the Cbornopteris separate from the Athyrium.Athyrium skinneri was a separate group,it together with the Anisocampium,Cornopteris,Pseudathyrium and Athyrium were recovered to be monophyletic.Its fimbriate lamellate folds spore morphology was different from Athyrium,Anisocampium,Cornopteris and Pseudathyrium,it phylogenetic location remains to be determined.Perine ornamentation,including 5 character states:fold,extervermiculate,ornate,rugate,tuberculate.Fold was the autapomorphy of Anisocampium,Cornopteris,Athyrium skinneri,Pseudathyrium alpestre,7 Section of Athyrium(Sect.Wallichiana,Sect.Yokoscentia,Sect.Rupestria,Sect.Biserrulata,Sect.Polystichoides,Sect.Dissitifolia and Sect.Spinulosa).Extervermiculate was the synapomorphies of 3 Section of Athyrium(Sect.Athyrium,Sect.Mackinnoniana,Sect.Otophora(Athyrium otophorum var.okanum-Athyrium viviparum,206-665 clade)).Ornate maybe was the synapomorphies of Sect.Otophora(Athyrium tozanense-Athyrium nigripes,232-634 clade).Only the fold of perine have the perine fold type,perine fold type including 5 character states:lamellate folds,lophate folds,reticulate folds,both lamellate folds and lophate folds,absence fold.Lamellate folds was the autapomorphy of Athyrium skinneri and Anisocampium;Reticulate folds was the synapomorphies of Pseudathyrium alpestre,5 Section of Athyrium(Sect.Rupestria,Sect.Biserrulata,Sect.Polystichoides,Sect.Dissitifolia and Sect.,Spinulosa).Lophate folds was the synapomorphies of Sect.Wallichiana.Perine surface subtle ornamentation,including 5 character states:papillate,granulate,tuberculate,mixed protuberance("papillate+granulate" or "tuberculate+granulate"),psilate.Granulate was the synapomorphies of Anisocampium,Cornopteris,5 Section of Athyrium(Sect.Polystichoides,Sect.Dissitifolia,Sect.Spinulosa,Sect.Mackinnoniana,Sect.Otophora).Mixed protuberance was the synapomorphies of Sect.Athyrium.