The Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK;
Am J Bot. 2007 Dec;94(12):2026-40. doi: 10.3732/ajb.94.12.2026.
Novel insights into the evolutionary history of a taxonomically complex tropical plant group were gained in this study using DNA sequence data. A molecular phylogenetic analysis of the newly circumscribed and expanded tribe Poranthereae (Phyllanthaceae) is presented. Sampling included 97 accessions for 63 of c. 120 species. Largely congruent results have been obtained from nuclear ribosomal ITS and plastid matK sequences. These analyses support the recognition of Andrachne and Leptopus as distinct genera. The deceptively similar Andrachne section Phyllanthopsis, Andrachne ovalis, and Leptopus decaisnei are separate lineages to be segregated. Zimmermannia and Zimmermanniopsis are embedded in Meineckia; Oreoporanthera is embedded in Poranthera; and Archileptopus is embedded in Leptopus. Andrachne section Pseudophyllanthus is polyphyletic, the two Madagascan endemics emerging as a sister clade to Meineckia. The noncontiguous distributions of Andrachne sensu lato and Leptopus sensu lato were found to be the result of separate evolutionary histories of morphologically similar clades, whereas Andrachne sensu stricto and Meineckia remain geographically disjunct. Actephila and Leptopus are sisters with a sympatric distribution in humid Asia. Presence of petals appears to be plesiomorphic for the tribe. Petals are reduced in Actephila and Oreoporanthera and lost in the Meineckia clade.
本研究利用 DNA 序列数据，深入了解了一个分类上复杂的热带植物群的进化历史。本文呈现了对新划定并扩展的 Poranthereae 族（藤黄科）的分子系统发育分析。采样包括 97 个材料，代表了约 120 种中的 63 种。核核糖体 ITS 和质体 matK 序列得到了基本一致的结果。这些分析支持将 Andrachne 和 Leptopus 识别为不同的属。形态上相似的 Andrachne 节 Phyllanthopsis、Andrachne ovalis 和 Leptopus decaisnei 是独立的谱系，需要分开。Zimmermannia 和 Zimmermanniopsis 嵌入在 Meineckia 中；Oreoporanthera 嵌入在 Poranthera 中；Archileptopus 嵌入在 Leptopus 中。Andrachne 节 Pseudophyllanthus 是多系的，两个马达加斯加特有种与 Meineckia 形成姐妹群。发现广义的 Andrachne 和 Leptopus 的不连续分布是形态相似的类群的独立进化历史的结果，而狭义的 Andrachne 和 Meineckia 仍然在地理上是隔离的。Actephila 和 Leptopus 是姐妹群，在潮湿的亚洲有共生分布。花瓣的存在似乎是该族的原始特征。花瓣在 Actephila 和 Oreoporanthera 中减少，在 Meineckia 类群中消失。
