Wu Jin-Feng, Jia Dong-Rui, Liu Rui-Juan, Zhou Zhi-Li, Wang Lin-Lin, Chen Min-Yu, Meng Li-Hua, Duan Yuan-Wen
School of Life Sciences, Yunnan Normal University, Kunming 650092, PR China.
School of Ecology and Environmental Science & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming 650091, PR China.
Plant Divers. 2021 Sep 23;44(3):290-299. doi: 10.1016/j.pld.2021.09.004. eCollection 2022 May.
Delimiting species requires multiple sources of evidence. Here, we delimited two varieties of (Gentianaceae) using several lines of evidence, including morphological traits and mating system in a sympatric population, phylogenetic relationships based on nrITS and cpDNA (rpl16) data, and complete chloroplast genome sequences. Comparative analysis of 21 morphological traits clearly separates the two varieties of . Examination of the flowering process and pollination treatments indicate that var. produces seeds via outcrossing, whereas var. produces seeds via mixed mating. Furthermore, hand-pollinated hybridization of the two varieties produced no seeds. Observations of pollinators showed that when bees began a pollination bout on var. they preferred to continue pollinating this variety; however, when they began a pollination bout on var. , they showed no preference for either variety. Phylogenetic analysis confirmed the monophyly of , which was further divided into two monophyletic clades corresponding to the two varieties. A large number of variants from the chloroplast genomes reflected remarkable genetic dissimilarities between the two varieties of . We recommend that the two varieties of should be revised as two species ( and ). Our findings indicate that varieties may have split into two separate species due to a shift in mating system, changes in flowering phenology and/or post-pollination reproductive isolation.
界定物种需要多种证据来源。在此，我们利用多种证据界定了龙胆科（Gentianaceae）的两个变种，包括同域种群中的形态特征和交配系统、基于nrITS和cpDNA（rpl16）数据的系统发育关系以及完整的叶绿体基因组序列。对21个形态特征的比较分析清楚地将两个变种区分开来。对开花过程和授粉处理的研究表明，[变种名称1]变种通过异交产生种子，而[变种名称2]变种通过混合交配产生种子。此外，两个变种的人工授粉杂交未产生种子。对传粉者的观察表明，当蜜蜂开始在[变种名称1]变种上进行一轮授粉时，它们更倾向于继续为该变种授粉；然而，当它们开始在[变种名称2]变种上进行一轮授粉时，它们对任何一个变种都没有偏好。系统发育分析证实了[属名]的单系性，该属进一步分为两个单系分支，分别对应于两个变种。叶绿体基因组中的大量变异反映了两个变种之间显著的遗传差异。我们建议将[属名]的两个变种修订为两个物种（[物种名称1]和[物种名称2]）。我们的研究结果表明，[属名]的变种可能由于交配系统的转变、开花物候的变化和/或授粉后生殖隔离而分裂为两个独立的物种。
