Rapid structural evolution of Dendrobium mitogenomes and mito-nuclear phylogeny discordances in Dendrobium(Orchidaceae)  

作　　者：Meng-Ting Wang Zhen-Yu Hou Chao Li Jia-Peng Yang Zhi-Tao Niu Qing-Yun Xue Wei Liu Xiao-Yu Ding 

机构地区：[1]College of Life Sciences,Nanjing Normal University,Nanjing 210097,China

出　　处：《Journal of Systematics and Evolution》2023年第5期790-805,共16页植物分类学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(Grant Nos 32070353,31670330,and 31900268);Natural Science Foundation of Jiangsu Province,China(BK20190699);Natural Science Fund for CollegesandUniversities in Jiangsu Province,China(19KJB180005));Modern Agriculture Project of Jiangsu Province,China(BE2019325);Forestry Science and Technology Innovation and Promotion Project of Jiangsu Province(SYF2021C0017).

摘　　要：Reconstructing mitochondrial genomes of angiosperms is extremely intricate due to frequent recombinations which give rise to varied sized in Dendrobium mitogenomes and their structural variations,even in most orchid species.In this study,we first sequenced two complete and five draft mitochondrial genomes of Dendrobium using next-generation and third-generation sequencing technologies.The mitochondrial genomes were 420538-689048 bp long,showing multipartite(multichromosomal)structures that consisted of variably sized circular or linear-mapping isoforms(chromosomes).The comparison of mitochondrial genomes showed frequent gene losses in Dendrobium species.To explore structure variations of mitochondrial genomes in vivo,we quantified copy numbers of five mitochondrial genes and DNA contents per mitochondrion.The gene copy numbers and the DNA contents showed extreme differences during Dendrobium development,suggesting dynamic structures of mitochondrial genomes.Furthermore,phylogenetic relationships of 97 accessions from 39 Dendrobium species were constructed based on 12 nuclear single-copy genes and 15 mitochondrial genes.We discovered obvious discordance between the nuclear and mitochondrial trees.Reticulate evolution was inferred from the species network analysis in Dendrobium.Our findings revealed the rapid structural evolution of Dendrobium mitochondrial genomes and the existence of hybridization events in Dendrobium species,which provided new insights into in vivo structural variations of plant mitochondrial genomes and the strong potential of mitochondrial genes in deciphering plant evolution history.

关 键 词：DENDROBIUM mitochondrial genome phylogenetic discordance structural evolution 

分 类 号：Q94[生物学—植物学]