A phylogenetic analysis of alyxieae (Apocynaceae) based on rbcL, matK, trnL intron, trnL-F spacer sequences, and morphological characters

作者：Endress Mary E^*; van der Ham Raymond W J M; Nilsson Siwert; Civeyrel Laure; Chase Mark W; Sennblad Bengt; Potgieter Kurt; Joseph Jeffrey; Powell Martyn; Lorence David; Zimmerman Ylva Maria; Albert Victor A

来源：Annals of the Missouri Botanical Garden, 2007, 94(1): 1-35.

DOI：10.3417/0026-6493(2007)94[1:APAOAA]2.0.CO;2

• Alyxieae
• Apocynaceae
• classification
• matK
• morphology
• phylogeny
• pollen
• rbcL
• systematics
• trnL
• trnL-F

Within Rauvolfioideae (Apocynaceae), genera have long been assigned to tribes based mainly on only one or two superficial fruit and seed characters. Taxa with drupaccous fruits were included in Alyxieae. To elucidate relationships within Alyxieae, we analyzed phylogenetically a data set of sequences from four plastid DNA regions (rbcL, matK, trnL intron, and trnL-F intergenic spacer) and a morphological data set for 33 genera of Apocynaceae, including representatives of all genera previously included in Alyxieae and two non-Apocynaceae species. Results of parsimony analysis indicate that Alyxieae as previously delimited are polyphyletic with most genera falling into two main clades. The Alyxia clade includes seven genera: Alyxia Banks ex R. Br., Lepinia Decne., Lepiniopsis Valelon, Pteralyxia K. Schum, and Condylocarpon Desf. together with Plectaneia Thouars. (earlier included in Plumericae) and Chilocarpus Blume (earlier included in Chilocarpeae). The Vinca clade includes eight genera: Cabucala Pichon, Petchia Livera, Rauvolfia L., Catharanthus G. Don, Vinca L, Neisosperma Raf., Ochrosia Juss., and Kopsia Blume. Vallesia Ruiz & Pav. and Anechiles Griseb, are not related to either clade and come out as sister to Aspidosperma Mart. & Zucc. (Aspidospermeae) and Thevetia L. (Plumerieae), respectively. The fruit and seed characters previously used to demarcate Alyxieae are homoplasious, as are other morphological characters such as style head structure and syncarpy versus apocarpy. Conversely, pollen morphology, which has not previously played much of a role in tribal delimitation, was shown to be the most useful morphological character for delimiting Alyxieae from other tribes of Rauvolfioideae.

• 出版日期2007