Systematic Study Of Silene Ascleviadea Complex

The Silene asclepiadea complex belongs to the Sect.Cucubaloideae subgroup,Subsect.Sinenses of Silene L.,including the Silene asclepiadea Franch.,S.szechuanensis F.N.Williams.,Silene adenantha Franchet,S.kermesina W.W.Smith.They are concentrated in Yunnan,Sichuan,Guizhou and other places in southwestern China.They are vine-like herbs in shape,with palmate veins in the leaves,two-different cymes,bell-shaped calyx,etc.as common features.Although this compound group has some common characteristics,its morphological variation is very complicated,especially in flower color,petals,leaf shape,etc.,so the predecessors have a lot of disputes about the species definition of this group.This research is based on the morphogeography research of the research group in the early stage,andit comprehensively analyzes three aspects from the molecular system research of nuclear genes and chloroplast gene fragments to pedigree geography and then to the whole chloroplast genome by extensive sampling.The changes in the morphological,molecular,and geographical distribution of the Silene asclepiadea complex have led to the following main research conclusions:1.In terms of phylogenetic research,based on the maximum likelihood method(ML)and Bayesian method(BI),auther constructed phylogenetic trees of 111 Silene genus species with ITS fragments.It involves total 17 groups plants of the Silene;then selected 21 plants that belong to the Sect.Cucubaloideae group of the Silene based on the four chloroplast fragments(rps16,matk,psb E-pet L,trn L-trn F)to preliminaryly explore the systematic relationship between the group species;finally,nuclear and chloroplast fragments of 21 species of Sect.Cucubaloideae group were connated to explore their laws.Phylogenetic tree result of the ITS segments support that the Sect.Cucubaloideae group based on morphology is a single line,it's support rates are BP=77.7/PP=0.7.In the single line of Sect.Cucubaloideae group,the Silene asclepiadea complex and its similar species Silene platyphylla Franch.,which have palm-shaped veins as the common feature,constitute a paraphyletic group,and the populations in different places are very complicated.The system relationship between them is worthy of further study.The phylogenetic tree constructed based on four chloroplast fragments(rps16,matk,psb E-pet L,trn L-trn F)does not agree with the classification based on morphological features.2.A new species that is called Silene jiaozishanensis Huan C.Wang?Xiao L.Liu sp.nov.was discovered,and the support rate reached BP=99.3/PP=1.0.The study found that although its morphology is similar to Silene asclepiadea Franch.,but they can be clearly distinguished in terms of petal color and calyx characteristics.The support rate of chloroplast-wide genome phylogeny analysis in the later period reached BP=100.3.In terms of pedigree geography study,the author used the 18 populations that contains 53 samples of the Silene asclepiadea Franch.complex,based on the ITS sequences and the chloroplast joint sequences(rps16+matk),to analyze genetic diversity and genetic structure of pedigree geography.The 53 samples of the ITS sequences were divided into 106 samples using DNAsp,then the 106 samples were divided into 74haplotypes based on DNAsp haplotype analysis(number Hap1-74).SAMOVA analysis divided 18 populations into 2 large groups and 4 subgroups.The two large groups were located in Ganluo County(GL)in Sichuan Province,southwestern Sichuan,and central to northern Yunnan.In addition,it was found that 74 haplotypes of the ITS sequences showed a trend of increasing distribution from the middle to the edge after statistical analysis.The populations located in Xiangyun County,Yunnan Province have the most abundant haplotype diversity.The expected value distribution of the population generated by DNAsp shows a single-peak curve,which indicates that there is obvious expansion in the population.The phylogeographic analysis based on the combination of chloroplast fragments(rps16+matk)found that the DNAsp haplotype analysis divided into 15haplotypes(Hap1-15)based on 53 samples,and the SAMOVA analysis divided 18populations into two large pedigree groups.The two large pedigree groups are located in Qiaojia County(QJ),Zhaotong City,Yunnan Province,and northwest Sichuan and central,northwest,and southeast Yunnan,which results differents ITS sequences.In addition,the haplotypes between the two groups have a high degree of genetic coincidence between different populations.The high inbreeding coefficient(F_ST=0.83)proves that the pedigree groupings of the two cp DNA genetic systems may have different origins.Different from the ITS sequence,the expected population distribution of the 18 populations based on the combination of chloroplast fragments generated by DNAsp showed a multimodal curve,indicating that there is no obvious expansion phenomenon in the population,and the population qualities is relatively stable.In addition,among the 18 populations based on the joint analysis of chloroplast fragments,the genetic variation among populations accounted for 80.14%,and within the population was only 16.97%,the results proved that the genetic variation mainly originated from among populations;while based on the ITS sequences,the opposite was true.The genetic variation within the population accounted for 60.64%,and the population within the population accounted for 26.85%.4.The chloroplast genome-wide annotation analysis and nucleic acid polymorphism analysis were performed on 4 species 5 samples of the Silene asclepiadea group,and the18 chloroplast genome sequences which were added in the gene library of the Silene genus,total 23 sequences.The results showed that the chloroplast genome size of the four species was 151872?152200 bp.The fully annotated chloroplast genome had a total of134 genes,of which there were 89 protein coding genes(CDS).The author analyzed all CDS genes of the 4 species and found that the biggest differences in the protein-coding genes of the 4 species were rpl32 CDS and ycf1 CDS.89 protein-coding genes nucleic acid polymorphism analysis of 4 species showed that the higher variability of protein-coding genes were ycf1(0.211),acc D and atp A(0.2105),ndh B and ycf2(0.20933),ycf15and ycf4(0.20917).5.Using the maximum likelihood method(ML)to construct a phylogenetic tree of23 chloroplast genome sequences of the Silene genus,it showed that the Silene asclepiadea complex formed a branch(support rate BP=100),which was a monophyletic group.S.adenopetala Raikova,S.asclepiadea Franch.and S.platyphylla Franch.together form a sister group relationship and become a single line(BP=100).If the species-level status of S.platyphylla Franch.is established,then the species-level status of S.adenopetala Raikova should also be recognized.It does not support Flora of China or other chronicles merged it into the classification treatment of Silene asclepiadea Franch..