目标:Vigna包括重要经济作物和野生物种。对Vigna物种的分子系统研究导致许多新世界(NW)物种的通用隔离。然而,有限的旧世界(OW)抽样留下了关于Vignas.s.种间和种内关系的问题
方法:非洲物种,包括推定的姐妹属Physostigma,在西北亲属的背景下进行了全面采样。对叶绿体matK-trnK和核核糖体ITS/5.8S(ITS)DNA区域进行了最大似然和贝叶斯推断分析,以解决OWVigna分类学问题。使用BEAST估算了发散日期,以确定系统发育中的关键节点。
结果:对matK和ITS数据的分析支持Vignas.s.:subg的五个分支。Lasiospron,减少的subg。Vigna,subg.Haydonia,subg.Ceratotropis,扩大的subg。Plectroropis,和一个进化枝,包括V.kirkii和V.stenophylla。克氏弧菌的基因组大小估计为601Mb,接近该属的总体平均值,而V.stophylla具有更大的基因组(810Mb),类似于一些Vignasubg。Ceratotropis或Plectrotrophis物种。
结论:前亚组。Vigna被简化为黄色和蓝色的花物种和subg。Plectrotropis扩大到大部分都是白人-,粉红色-,和紫花物种。NW和OWVigna谱系之间的分裂年龄为〜6-7Myr。基因组大小估计不能排除蛇形弧菌的多倍体或杂种起源,可能涉及Vignasubg的灭绝血统祖先。Ceratotropis或Plectroropis,如网络和系统发育分析所示。根据这些结果,建议进行分类修订。
OBJECTIVE: Vigna includes economically vital crops and wild species. Molecular systematic studies of Vigna species resulted in generic segregates of many New World (NW) species. However, limited Old World (OW) sampling left questions regarding inter- and intraspecific relationships in Vigna s.s.
METHODS: African species, including the putative sister genus Physostigma, were comprehensively sampled within the context of NW relatives. Maximum likelihood and Bayesian inference analyses of the chloroplast matK-trnK and nuclear ribosomal ITS/5.8 S (ITS) DNA regions were undertaken to resolve OW Vigna taxonomic questions. Divergence dates were estimated using BEAST to date key nodes in the phylogeny.
RESULTS: Analyses of matK and ITS data supported five clades of Vigna s.s.: subg. Lasiospron, a reduced subg. Vigna, subg. Haydonia, subg. Ceratotropis, an enlarged subg. Plectrotropis, and a clade including V. kirkii and V. stenophylla. Genome size estimates of 601 Mb for V. kirkii are near the overall mean of the genus, whereas V. stenophylla had a larger genome (810 Mb), similar to some Vigna subg. Ceratotropis or Plectrotropis species.
CONCLUSIONS: Former subg. Vigna is reduced to yellow- and blue-flowered species and subg. Plectrotropis is enlarged to mostly all white-, pink-, and purple-flowered species. The age of the split between NW and OW Vigna lineages is ~6-7 Myr. Genome size estimates cannot rule out a polyploid or hybrid origin for V. stenophylla, potentially involving extinct lineage ancestors of Vigna subg. Ceratotropis or Plectrotropis, as indicated by network and phylogenetic analyses. Taxonomic revisions are suggested based on these results.