【摘要】 裂萼苔[Chiloscyphus polyanthos(L.)Corda]隶属于齿萼苔科叶苔目，是苔藓植物中既能水生又能陆生的物种，也是研究植物登陆与演化的重要类群之一。本文对裂萼苔叶绿体基因组的结构和系统发育进行了分析，并将其与GenBank中现有的四个叶苔目物种(Bazzania praerupta(Reinw.,Blume et Nees)Trevis.、Heteroscyphus argutus(Reinw.,Blume et Nees)Schiffn.、Herbertus javanicus(Steph.)H.A.Mill.和Plagiochila chinensis Steph.)进行基因组比较。研究结果表明：(1)裂萼苔叶绿体基因组全长116988 bp, GC含量为33.9%,呈典型的四分体结构，共注释130个基因，其中包括85个编码基因、37个tRNA基因和8个rRNA基因；(2)共检测到35个简单序列重复(SSRs),其中以单核苷酸(A/T)为主，且发现36个散在重复序列，回文重复最为丰富；(3)IR边界分析显示，裂萼苔与其他四个叶苔目物种在JLB、JSB和JSA边界具有显著差异；(4)筛选出四个高度变异的基因或区域，分别为trnQ(UUG)-trnK(UUU)、cysT-trnL(UAG)、ycf1-1-trnN(GUU)和ycf2,它们可以作为叶苔目的分子标记，未来可用于该类群的系统发育研究；(5)基于rbcL标记的系统发育分析表明，裂萼苔与该属中Chiloscyphus pallescens的亲缘关系较近。本研究为裂萼苔的叶绿体基因组结构、系统发育以及进化动态提供了宝贵的数据支持。同时为裂萼苔的分类学研究、物种进化探讨以及植物登陆的进一步研究提供了重要的理论依据。更多还原

【Abstract】 Chiloscyphus polyanthos(L.)Corda, classified within the family Lophocoleaceae of the order Jungermanniopsida, represents a bryophyte species capable of thriving in both aquatic and terrestrial environments. This versatility renders it a crucial subject for studies on plant land colonization and evolutionary processes.In the present study,we conduct a comprehensive analysis of the chloroplast genome structure and phylogenetic relationships of Chiloscyphus polyanthos,comparing it with four other species from Jungermanniopsida available in GenBank,namely Bazzania praerupta( Reinw.,Blume et Nees) Trevis.,Heteroscyphus argutus( Reinw.,Blume et Nees) Schiffn.,Herbertus javanicus( Steph.) H.A.Mill.and Plagiochila chinensis Steph.The key findings of the study are summarized as follows:( 1) The chloroplast genome of Chiloscyphus polyanthos has a length of 116,988 base pairs,with a GC content of 33.9%,and exhibits a typical quadripartite structure.The genome annotation has identified 130 genes,including 85 protein-coding genes,37 tRNA genes,and 8 rRNA genes.( 2) The analysis of simple sequence repeats( SSRs) has revealed 35 repeats,with single-nucleotide motifs( primarily A/T) predominating.Additionally,36 dispersed repetitive sequences are identified,with palindromic repeats being the most abundant.( 3) Examination of the inverted repeat( IR) boundary regions demonstrates significant differences between Chiloscyphus polyanthos and the other four Jungermanniopsida species,particularly at the JLB,JSB,and JSA boundaries.( 4) Four highly variable genes or regions have been identified: trnQ( UUG)-trn K( UUU),cysT-trn L( UAG),ycf1-1-trnN( GUU) and ycf2.These regions can serve as molecular markers for Jungermanniopsida and hold potential for future phylogenetic studies.( 5) Phylogenetic analysis based on the rbcL marker indicates that Chiloscyphus polyanthos shares a close evolutionary relationship with Chiloscyphus pallescens. The findings of this study contribute valuable data to the understanding of the chloroplast genome structure,phylogeny,and evolutionary dynamics of Chiloscyphus polyanthos.Furthermore,these results offer important theoretical support for advancing taxonomic research,elucidating species evolution,and investigating plant land colonization in bryophytes.更多还原