大麻科分子系统学研究与分化时间估算

	大麻科分子系统学研究与分化时间估算; Phylogenomics and Divergence Time Estimation of Cannabaceae
	付小刚
导师	伊廷双
摘要	Cannabaceae belongs to Rosales of nitrogen-fixing clade, which contains ca. 10 genera and 182 species. This family shows a cosmopolitan disjunct distribution in tropical, subtropical and temperate regions of both the New World and the Old World. Many species in Cannabaceae have important economic and ecological values. Previous phylogenetic studies have progressed in resolving some intergeneric relationships of this family except for the phylogenetic relationships between Gironniera Gaud. and Lozanella Greenm. mainly based on morphological traits, chloroplast and ribosomal DNA fragments. However, many deep internodes within Cannabaceae remained unresolved due to limited taxon sampling or fewer available markers. Therefore, a stable and reliable phylogenetic framework of Cannabaceae is still lacking. In this study, we explored with an expanded taxon sampling and performed phylogenomic analyses utilizing 90 targeted single or low-copy orthologous nuclear genes, as well as a number of non-targeted regions (e.g. chloroplast and ribosome DNA regions) from Hyb-seq integrated with published chloroplast and ribosome DNA regions from GenBank and literature for the first time. In addition, we inferred patterns of captured nuclear gene-tree concordance and conflict with species tree (ASTRAL). Meanwhile, we estimated the divergence time of Cannabaceae with treePL based on ML tree inferred by concatenated captured nuclear genes and 5 fossil records. The main results of this study are as follows: 1. Phylogenetic relationships in Cannabaceae The phylogenetic analysis results of the three types of molecular data (captured nuclear genes, chloroplast and ribosome DNA regions) used were inconsistent. The phylogenetic relationships highly supported in this study include: Cannabaceae and all genera except Trema Lour. and Celtis L. are monophyletic. Aphananthe Planch. was resolved as the first diverged genus, which is sister to all other genera in Cannabaceae. Gironniera, Lozanella, Celtis II were successively diverged. However, the consistency and conflict analysis between the captured nuclear gene-tree indicated that there were obvious gene conflicts in the phylogenetic position of Lozanella and the Celtis II clade. For other intergeneric relationships, Cannabis L. is sister to Humulus L., Pteroceltis Maxim. and Chaetachme Planch. are sisters, and Parasponia Miq. is nested within Trema. Phylogenetic analysis results of captured nuclear genes highly supported the (Cannabis, Humulus) clade and the (Chaetachme, Pteroceltis) clade form a sister relationship (abbreviated as the CHCP clade), and then the CHCP clade is sister to the Trema (Parasponia) clade with a low support, but it showed obvious gene conflicts and differred from the result of chloroplast phylogenetic analyses. Finally, the Celtis I clade is sister to a clade formed by the CHCP clade and the Trema (Parasponia) clade.
	2021-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74513
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	付小刚. 大麻科分子系统学研究与分化时间估算, Phylogenomics and Divergence Time Estimation of Cannabaceae[D],2021.

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