石松科的分子系统学研究

发布时间：2018-01-11 13:12

  本文关键词：石松科的分子系统学研究　出处：《重庆师范大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 石松科 单系群 分子系统

【摘要】：石松科(Lycopodiaceae)约388种,全球广布,主产热带地区。围绕石松科已开展了细胞学、形态学、解剖学、分子系统学等方面的研究,提高了对石松科多样性和进化的理解,但主要问题仍然存在:(1)形态特征简单,根据形态进行分类非常困难;(2)取样不够和使用的基因片段较少,属间关系没有被很好的确立和已被承认的大部分属的单系没有被很好检测。因此,迫切需要大范围取样和增加基因片段对石松科进行分子系统学研究。本研究对石松科取样323个约130种,运用5个叶绿体片段(rbcL,atpA,trnL-F,psbA-trnH,rps4-trnS),综合最大似然法和最大简约法重建了石松科的分子系统关系。研究结果显示:(1)石松科可分为三个大支,支持将石松科分为三个亚科,即石杉亚科(Huperzioideae)、石松亚科(Lycopodioidieae)和小石松亚科(Lycopodielloideae);(2)石松亚科和小石松亚科的亲缘关系较近,而与石杉亚科的亲缘关系较远;(3)三个大支可进一步分为17个支,其中16个支分别代表16个属,与PPG I的分类处理一致,而Lycopodium serpentinum形成了独立的支。在这16个属中,除石杉属(Huperzia)外,其余15个属的单系均得到了很好的支持(ML BS≥96,MP JK≥86),石杉属的单系勉强得到支持(ML BS=50,MP JK=55)。研究显示Phylloglossum形成的长枝吸引降低了石杉属单系的支持率,在排除Phylloglossum后,石杉属的单系得到了较高支持(ML BS=80,MP JK=92)。尽管Phylloglossum和石杉属为姊妹群关系,但两者形态差异较大,遗传距离远,故本研究接受石杉属和Phylloglossum均作为独立的属。因此,本研究结果支持PPG I对石松科的分类处理,将石松科分为三个亚科16个属,即石杉亚科,包括石杉属(Huperzia),马尾杉属(Phlegmariurus),Phylloglossum;小石松亚科,包括Lateristachys,小石松属(Lycopodiella),垂穗石松属(Palhinhaea),拟小石松属(Pseudolycopodiella);石松亚科,包括Austrolycopodium,Dendrolycopodium,扁枝石松属(Diphasiastrum),Diphasium,藤石松属(Lycopodiastrum),石松属(Lycopodium),Pseudodiphasium,Pseudolycopodium,Spinulum。对于Lycopodium serpentinum,Kunze于1846年发表,这个种均不与拟小石松属和小石松属形成单系群,而是独立形成一支并与垂穗石松属构成姊妹群关系,由于本研究数据仅包括了来自GenBank一个序列rbcL,所以不作处理,其系统位置需要进一步研究。
[Abstract]:There are 388 species of Lycopodiaceae, which are widely distributed all over the world and are mainly produced in tropical regions. Cytology, morphology, anatomy, molecular systematics and so on have been studied around the family Lycopodiaceae. The understanding of the diversity and evolution of Pinaceae is improved, but the main problem is that the morphological characteristics are simple, and it is very difficult to classify them according to their morphology. (2) inadequate sampling and use of fewer gene fragments, poorly established intergeneric relationships and poorly tested monophyls of most of the recognized genera. There is an urgent need for extensive sampling and increasing gene fragments to study the molecular phylogeny of Pinaceae. In this study, 323 species of Pinaceae were sampled and 5 chloroplast fragments were used to study the molecular phylogeny of Pinaceae. TrnL-FU psbA-trnHN rps4-trnS. The molecular phylogenetic relationship of Pinaceae was reconstructed by using the maximum likelihood method and the maximum minimization method. The results show that the family of Pinaceae can be divided into three large branches, which supports the division of Pinaceae into three subfamilies. They are Huperzioideaeae, Lycopodioidieaeae and Lycopodielloideaeae; (2) the relationship between the subfamily of Pinaceae and the subfamily of Pinaceae is close, but the relationship with the subfamily of Taxodiaceae is far away. (3) three large branches can be further divided into 17 branches, of which 16 branches represent 16 genera respectively, which is consistent with the classification of PPG I. Lycopodium serpentinum forms a separate branch, except for Huperzia, which belongs to 16 genera. The other 15 monophyls were all well supported by MLBS 鈮，

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