Phylogenetic Analysis for a New Classification of the Phyllodium Group of Leguminosae Tribe Desmodieae

Abstract

The tribe Desmodieae (Leguminosae subfam. Papilionoideae) consists of three groups: Desmodium, Lespedeza and Phyllodium. The Phyllodium group includes 12 genera: Akschindlium, Aphyllodium, Arthroclianthus, Dendrolobium, Droogmansia, Hanslia, Nephrodesmus, Ohwia, Ougeinia, Phyllodium, Tadehagi and Verdesmum. Phylogenetic trees for this group were constructed based on nine chloroplast DNA (cpDNA) regions (5ʹtrnK intron, ndhJ-trnF-trnL, trnT-trnL, trnG-trnS, trnQ-rps16, trnL-rpl32, rpl16 intron, trnC-rpoB, ndhA intron) and two nuclear ribosomal DNA (nrDNA) spacers (ITS and ETS). Except for Verdesmum lacking DNA data, the Phyllodium group is monophyletic in the nrDNA tree, while the group is paraphyletic in the cpDNA tree with Ougeinia being sister to Ototropis of the Desmodium group, although the remaining genera form a monophyletic group. The group comprises six clades: Ougeinia-Ototropis (in the cpDNA) or Ougeinia (in the nrDNA), Aphyllodium, Dendrolobium, Ohwia, Phyllodium and Tadehagi clades, each of which has a high support value. Dendrolobium multiflorum was placed within the Phyllodium clade in both phylogenetic trees. As the result, the species is transferred to Phyllodium.