Abstract Detail

Systematics Section / ASPT

Jelinski, Nic [1], Van Ee, Benjamin [1], Hipp, Andrew [1], Berry, Paul E. [1].

Phylogenetic relationships within Croton alabamensis, a rare shrub disjunct between Texas and Alabama, inferred by DNA sequence data and AFLP analysis.

Croton alabamensis (Euphorbiaceae) is a rare shrub known from a few populations on the Edwards Plateau in Texas and the Tuscaloosa area of northern Alabama. We performed maximum parsimony analyses of DNA sequences from the nuclear ITS and chloroplast trnL-F regions from 9 Texas accessions, 7 from Alabama, and 5 outgroup taxa. This produced a polytomy within C. alabamensis involving the individual Texas accessions and a single clade of Alabama accessions. AFLP analyses were performed using two selective primer pairs on a larger sampling (22 from Texas, 17 from Alabama) to further discriminate population structure. In an unrooted distance analysis, the populations from the Cahaba and Black Warrior watersheds in Alabama form two distinctly separated groups, whereas in Texas geographically distinct populations are less resolved. The outgroups attach to the same node as the Texas accessions, and there is high bootstrap support for the branch separating this node from the node to which the Alabama accessions attach. Both the sequence and AFLP data support the same relationships, with the AFLP data providing finer resolution among disjunct populations.

1 - University of Wisconsin-Madison, Botany, 430 Lincoln Drive, Madison, Wisconsin, 53706-1381, USA

Keywords:
Croton alabamensis
disjunction
AFLP
ITS
trnL-F
population structure.

Presentation Type: Paper
Session: 30-2
Location: Cottonwood B (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 8:30 AM
Abstract ID:195