A new sectional classification of Lachenalia (Asparagaceae) based on a multilocus DNA phylogeny

Lachenalia J.Jacq. ex Murray (Asparagaceae; Scilloideae; Hyacintheae) is a large and morphologically diverse genus of more than 140 bulbous species endemic to southern Africa. Previous attempts to infer a well resolved and robustly supported phylogeny of Lachenalia using Sanger sequencing of candidate loci and/or morphological characters have been largely unsuccessful. Consequently, the current infrageneric classification is artificial and there is a need to explore alternative avenues to produce a phylogenetic classification. In this paper we present a novel phylogenetic hypothesis for Lachenalia inferred using maximum likelihood and coalescent-based species tree estimation (ASTRAL) as applied to 378 hybrid-enrichment loci. Our tree is well resolved and well supported, providing strong support for a monophyletic radiation of the genus in southern Africa and a solid foundation for a revised infrageneric classification. The well-supported placement of L. isopetala Jacq. as sister to Lach...立金花属（Lachenalia J.Jacq. ex Murray，天门冬科（Asparagaceae）、风信子亚科（Scilloideae）、风信子族（Hyacintheae））是一个物种丰富、形态多样的球根植物属，包含140余种南非特有物种。此前通过候选基因座的桑格测序（Sanger sequencing）及/或形态性状来构建立金花属高分辨率、高支持率系统发育树的尝试，大多未能获得成功。因此，当前该属的属下分类为人为划分，亟需探索新路径以构建符合系统发育关系的分类系统。本研究基于378个杂交富集基因座，通过最大似然法（maximum likelihood）与基于溯祖理论的物种树估算工具（ASTRAL），构建了立金花属全新的系统发育假说。本次构建的系统发育树分辨率优异、支持度充足，为立金花属在南非的单系辐射演化提供了强有力的支持，同时也为修订属下分类系统奠定了坚实基础。本次研究得到高支持度的结果显示，L. isopetala Jacq. 与Lach... 互为姐妹类群。