| Dryopteris,with more than 400 species,is one of the largest genera in Dryopteridaceae,and world-widely distributed in the world.D.cycadina group,a problematic group containing about 14 species in Zhejiang Province,which are similar to each another.The variation patterns of the group are complicated,and they are difficult to distinguish.For example,in the Flora of China(Wu 2000),D.fengyangshan was integrated into D.cycadina,and D.shuichangensis has yet to be studied,and Flora of Zhejiang(Zhang 1993)Among them,D.fengyangshanensis and D.shuichangensis are both independent species.Based on the literature and specimen survey,field investigation,togather with the evidence of morphology and molecular data,the comprihasive analyses to deal with the clarification of D.cycadina group were conducted.The main results are as follows:(1)Spore morphology of D.cycadina and its allied species were observed.The spores of D.cycadina and its allied species were symmetrical on both sides,oval in polar view and bean-shaped or nearly oval in equatorial view.They were single fissure,with the size 43.13(29.82?52.08)×30.80(22.36?36.73)?m and 1.13×10~4?5.14×10~4?m~3in volume.The spores of D.wuyishanica showed the largest,with spore size being 52.08(42.00?56.00)?m×36.19(28.00?44.80)?m,and the volume is about 5.41×10~4?m~3;the smallest individual is D.hangchowensis which has the spore size of 29.82(28.00?35.00)?m×24.22(21.00?28.00)?m and a volume of about 1.13×10~4?m~3.The ornamentation of spore surface can be divided into short lophate ornamentation(including D.cycadina,D.fengyangshanensis,D.scottii,D.namegatae,D.dickinsii,D.wuyishanica,D.shuichangensis,D.whangshanensis),long lophate ornamentation(D.tokyoensisi),tuberculate ornamentation(D.hangchowensis),1amellate ornamentation(D.commixta,D.atrata),or fenestrate ornamentation(D.handeliana).The morphological characters of spores had obvious differences among D.cycadina,D.tokyoensisi,D.hangchowensis,D.commixta,and D.handeliana,which revealed certain taxonomic significance.(2)Scale morphology of D.cycadina and its allied species were observed.The scales on the rhizome are lanceolate or linear-lanceolate,mostly brown(including D.cycadina,D.namegatae,D.wuyishanica,D.shuichangensis),rarely yellow(D.handeliana,D.whangshanensis),length being 1.10?2.42 cm,width being 0.12?0.23cm,apex multi-tailed acuminate(containing D.cycadina,D.namegatae,D.wuyishanica,D.shuichangensis),rarely acuminate(D.handeliana,D.whangshanensis),with entire margin;The scales on the base of the petiole are linear-lanceolate,lanceolate or broad-lanceolate,mostly brown,sparsely yellow(D.whangshanensis)or light yellow(D.tokyoensisi),length being 1.08?2.02 cm,width being 0.14?0.27 cm,the apex is mostly caudate acuminate,rarely acuminate(involving D.fengyangshanensis,D.handeliana,D.namegatae,D.tokyoensisi),with entire margin,sparse serrations or spinous teeth at the bottom;The scales on the petiole are linear-lanceolate,diamond-lanceolate,lanceolate or broad-lanceolate,mostly brown,sometimes yellow(D.whangshanensis)or light yellow(D.dickinsii,D.tokyoensisi),The apex is mostly caudate acuminate,rarely acuminate(D.whangshanensis,D.tokyoensisi),entire at margin,with sparse serrations,ciliary teeth or spinous teeth at the lower part;The scales on the leaf shafts are linear-lanceolate or diamond-lanceolate,brownish,sparsely yellowish(including D.handeliana,D.dickinsii,D.whangshanensis,D.tokyoensisi),with apex caudate acuminate and entire margin,with sparse serrations,ciliary teeth,or spinous teeth at the lower part.The shape,size,edge characters and apex shape of different parts of the same species are different,and the color is basically stable;the scale shape,size,edge characters,apex shape and color of different species are different;it revealed certain taxonomic significance.(3)22 morphological characters of 13 species with 136 individuals of D.cycadina and its allied species were analyzed by PCA(principal component analysis).The results showed that the main distinguishing characters to the group were shape of pinnasect lobes,pinnae tip and length,the color of scales at the base of petiole and row number of sacs.D.tokyoensisi,D.hangchowensis,D.handeliana,D.whangshanensis and D.shuichangensis are highly differentiated from each other,so they are recognized here.While D.cycadina,D.atrata,D.fengyangshanensis,D.commixta,D.namegatae,D.dickinsii and D.scottii could not be distinguished.(4)Phylogenetic tree was constructed by combining trn L-F,psb A-trn H and rps4-trn S of D.cycadina and its 12 allied species.The analysis shows that it can be divided into five branches in the group of D.cycadina:the 3 individuals of D.tokyoensisi clustered into a branch,which is located at the base(PP=1,BS=100%),which can be separated from other species;3 individuals of D.shuichangensis and 4individuals of D.whangshanensis gather into a branch(PP=1,BS=100%),but the two species cannot be separated from each other;3 individuals of D.scottii form an independent branch(PP=1,BS=100%);D.dickinsii 4 Individuals and 3 individuals of D.handeliana form a group(PP=1,BS=100%),and the two species cannot be separated;16 individuals of D.cycadina,6 individuals of D.atrata,and D.fengyangshanensis Three individuals,three individuals from D.commixta,one individual from D.hangchowensis,and three individuals from D.namegatae gathered into the last branch(PP=1,BS=100%),and they could not be separated from each other.(5)Based on the above-mentioned results,9 species of D.cycadina group in Zhejiang were recognized,and I agreed to merge D.atrata into D.commixta,D.fengyangshanensis,D.namegatae,and D.wuyishanica being reduced to D.cycadina.It was not supported that D.shuichangensis considering the hybrid between D.dickinsii and D.whangshanensis. |
PDF Full Text Request