Phylogenetic Evaluation Of Chamaelirium Chinense Complex(Melanthiaceae)

The Chamaelirium belongs to Melanthiaceae,distributing in eastern North America,Japan,Southeast Asia and southern China.The subsection Cathayana includes five recorded species of the genus from Asia,of which four were distributed in southeast China and one in Vietnam and Laos.The diagnostic characters among Chamaelirium chinense complex(four species distributed in southeast China:Chamaelirium chinense(s.s.),C.shiwandashanense,C.nanlingense,C.viridiflorum)remain unclear,and the distribution of these species is mostly sympatric or adjacent.So we focused on the complex to evaluate the phylogenetic process and to determine the species' boundaries of this subsection.In this study,we collected 10 populations of these four species from type localities and other distribution areas,as well as outgroups,for morphological anatomy and molecular phylogenetic analyses.Morphologically,we observed the vegetative and floral characteristics for individuals and populations,compared the correlation of morphological characteristics among populations and analyzed their variations.Molecularly,mat K,rbc L,psb A-trn H,ndh F and G3 pdh were selected,with 190 newly obtained sequences,for constructing phylogenetic trees and analyzing the genetic background and phylogenetic relationships among species of the Chamaelirium chinense complex.The results are presented:1.Morphological observation showed that the vegetative,fruit and seed characteristics of Chamaelirium chinense(s.s.)were uniform and relatively stable in most populations.Flower characters of C.chinense(s.s.)showed an integrated variation that flowers actinomorphic,zygomorphic or asymmetric,tepals 0-6,spathulate-linear to filiform,stamens 0-6.While Chamaelirium shiwandashanense,C.nanlingense and C.viridiflorum don't have obvious difference in vegetative,fruit and seed form C.chinense(s.s.),and their flower characters were relatively stable and within the variation of Chamaelirium chinense(s.s.).PCOA and UPGMA analysis showed that clustering did not occur in the Chamaelirium chinense complex.2.Molecular phylogenetic results revealed that Chamaelirium chinense complex is monophyly and is the sister group of subsection Chionographis.Populations within the complex have slightly different positions on phylogenetic trees constructed by different molecular sequences.However,considered the complex internal nodes of phylogenetic tree from concatenated plastid loci and nuclear gene,it is obvious that Chamaelirium viridiflorum and population LSZ of C.chinense(s.s.)are sister groups,C.nanlingense and population MS of C.chinense(s.s.)are sister groups.Furthermore,the C.shiwandashanense,C.chinense(s.s.)(populations DMS,MS,DYS,JWS,LSZ),C.viridiflorum and C.nanlingense form a group together.These evidences show that Chamaelirium chinense(s.s.)is polyphyletic,and the related species C.shiwandashanense ? C.nanlingense and C.viridiflorum can't be independently species.3.Based on the morphological and molecular evidences,this study proposed that Chamaelirium shiwandashanense,C.nanlingense and C.viridiflorum were treated as synonyms of C.chinense(s.l.).