Certamen Melastomataceis XXXIII
Certamen Melastomataceis XXXIII
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野牡丹 XXXIII
作者：
John J Wurdack
长期以来，Dissotishas 一直被认为是非洲野牡丹科物种最丰富的属，但其诊断特征从未在明确的系统发育背景下得到检验。在之前的一项研究中，我们发现了一个由“Dissotisand 盟友”组成的大型分支，但对其通用限制知之甚少。在这里，我们使用从两个核（nrETS，nrITS）和两个质体标记（ndhF，psbK-psbL）生成的序列，展示了非洲野牡丹科的近乎完整的系统发育，重点是Dissotis和盟友，对代表69个物种（包括外群）的94个种质进行了采样。我们使用最大似然法、简约法和贝叶斯方法推断系统发育关系，并根据我们的分子树提出修订后的 Dissotis 和盟友的通用分类。此外，我们重建了非洲野牡丹科 20 个重要形态特征的祖先状态。Dissotis 和 Antherotoma 先前界定的属多系，而先前识别的 Dissotissubg.Dissotis 的所有四个科都是单系的（即 Dissotis、Macrocarpae、Sessilifoliae 和 Squamulosae 科）。我们还发现了一个由 D 组成的进化枝。刚果人，A.塞内加尔，A.隐秘的和Nerophila gentianoides 加上早期在非洲Osbeckia 处理过的物种。祖先特征重建表明Dissotiss.l 不存在明确的形态学共谱。特别是，雄蕊二态性的特征表现出同质性。然而，组成 Dissotis 和盟友的各个进化枝均通过一到几个形态特征来诊断。鉴于这些结果，我们建议对非洲野牡丹科的分类进行以下修改：（1）描述了5个新属，Almedanthus（forDissotis pachytricha）、Eleotis（forD.sect.Sessilifoliae）、Feliciotis（forD. sect.Macrocarpae）、Pyrotis（forD. gilgiana）和蔷薇茶（D.sect.Squamulosae）； (2) 恢复了Nerophilais属，并扩大了范围，包括Antherotoma senegambiensis、A.秘密，D.刚果人，D. pauciflora 和早期在非洲 Osbeckia 处理过的三个物种； (3)Dissotiss.str 的范围。减少到六种； (4) 恢复单种德罗丝虫属； (5)将先前置于Dissotis中的两个物种转移至Antherotoma中。为了完成我们的属名重新调整，12 个新同义词和 58 个新组合在物种水平或低于物种水平上生效。总共指定了 40 个选型或新型。为非洲野牡丹科提供了修订后的索引，包括目前在 Dissotisand allies.Dissotis leonensis（D.subg.Paleodissotis 的类型和唯一种）中识别的所有九个属，以及单种 Cailliella 和 Dionychastrum 仍未采样。
Dissotishas long been regarded as the most species‐rich genus of African Melastomataceae, yet its diagnostic characters have never been examined in an explicitly phylogenetic context. In a previous study, we recovered a large clade consisting of “Dissotisand allies” but with poorly understood generic limits. Here we present a nearly complete phylogeny of African Melastomateae with focus onDissotisand allies using sequences generated from two nuclear (nrETS, nrITS) and two plastid markers (ndhF,psbK‐psbL), sampling 94 accessions representing 69 species including outgroups. We infer phylogenetic relationships using maximum likelihood, parsimony and Bayesian approaches and propose a revised generic classification ofDissotisand allies based on our molecular trees. In addition, we reconstruct the ancestral state of 20 important morphological characters of African Melastomateae.DissotisandAntherotomaas previously circumscribed are polyphyletic, while all four of the previously recognised sections ofDissotissubg.Dissotisare monophyletic (i.e., sectionsDissotis,Macrocarpae,SessilifoliaeandSquamulosae). We also recovered a clade consisting ofD. congolensis,A. senegambiensis,A. clandestinaandNerophila gentianoidesplus the species earlier treated in AfricanOsbeckia. Ancestral character reconstruction indicates there are no unambiguous morphological synapomorphies forDissotiss.l. In particular, the character of staminal dimorphism is shown to be homoplasious. However, the individual clades making upDissotisand allies are each diagnosed by one to several morphological characters. In view of these results, we propose the following changes for the classification of African Melastomateae: (1) five new genera are described,Almedanthus(forDissotis pachytricha),Eleotis(forD.sect.Sessilifoliae),Feliciotis(forD. sect.Macrocarpae),Pyrotis(forD. gilgiana) andRosettea(forD.sect.Squamulosae); (2) the genusNerophilais reinstated with an expanded circumscription to includeAntherotoma senegambiensis,A. clandestina,D. congolensis,D. paucifloraand three species earlier treated in AfricanOsbeckia; (3) circumscription ofDissotiss.str. is reduced to six species; (4) the monospecific genusDerosiphiais reinstated; and (5) two species previously placed inDissotisare transferred toAntherotoma. To complete our generic realignment, 12 new synonyms and 58 new combinations are effected at or below the species level. A total of 40 lecto‐ or neotypes are designated. A revised key is provided for African Melastomateae, including all nine genera presently recognised inDissotisand allies.Dissotis leonensis(type and only species ofD.subg.Paleodissotis) together with the monospecificCailliellaandDionychastrumremain unsampled.