ON THE PHYLOGEOGRAPHY OF THE SOUTHEASTERN SPECIES OF THE GENUS DALEA L. (FABACEAE) USING A PHYLOGENETIC APPROACH

Abstract

The genus Dalea (Fabaceae) consists of approximately 160 species with a few species being geographically widespread, and most of the genus being endemic to restricted areas with calcareous substrates. A previous study (McMahon and Hufford, 2004) looked at the phylogeny of the tribe which Dalea belongs to, Amorpheae, and one other phylogenetic study (Diggs, 2013) has been conducted on several species in the genus itself, mainly from the mid-west and coastal plains of Alabama. This study focuses on the phylogeny and phylogeography of Dalea species from the Gulf Coastal Plain, including D. carnea, D. carthagenesis var. floridana, D. feayi, D. pinnata var. pinnata,D. pinnata var. trifoliata, D. adenopoda, D. mountjoyae, and D. albida compared to two species in the genus Amporpha (Fabaceae) a closely related genus. Phylogeny for Dalea will be determined by DNA sequences taken from the plastid trnK/matK intron, and the nuclear ribosomal ITS1, 5.8S, and ITS2, and compared to sequences obtained from previous phylogenetic studies of Dalea (Diggs, 2013). DNA sequences from all specimens have been obtained for the nuclear loci ITS1 and a majority for matK, and preliminary phylogenetic trees show taxa falling out in line with previous taxonomy.

Key words: Dalea; Amorpheae; Fabaceae; ITS; phylogeny; phylogeography; trnK/matK; Gulf Coastal Plain; calcareous substrate.