Abstract Detail

Systematics Section / ASPT

Shaw, Joey [1], Small, Randall [2].

Concordant Phylogeographic patterns of the chloroplast and nuclear genomes in the North American plum syngameon (Prunus subgenus Prunus section Prunocerasus; Rosaceae).

The North American plums (Prunus subgenus Prunus section Prunocerasus; Rosaceae) are infamous for their very poor development of reproductively isolating barriers. Many North American plum species are interfertile in many combinations and natural hybrids blur nearly all morphologically-based taxonomic boundaries. In previous studies, we showed that the North American plums are monophyletic and that chloroplasts were geographically distributed, rather than being taxonomically distributed. These earlier studies concluded that frequent hybridization has allowed regional sharing of the three primary chloroplast haplotypes among the 17 putative taxa in the section. Here we examined the relationships of the North American plums using the nuclear encoded NADP+ dependant sorbitol-6-phosphate dehydrogenase gene (s6pdh) to test the phylogenetic / phylogeographic conclusions of our earlier studies. The results show that most section Prunocerasus taxa are clearly not monophyletic. Although some nuclear haplotypes are more common in some taxa, few are exclusive. Coupled with evidence from our previous studies, these results support the hypothesis that North American plums are an evolutionarily complicated species complex, or syngameon. Another important conclusion to this study highlights the problem of undersampling in closely related groups of species, but these results also show that problems can be circumvented by increased sampling.

1 - University of Tennessee, Chattanooga, Department of Biological and Environmental Sciences, 215 Holt Hall, Department 2653, 615 McCallie Avenue, Chattanooga, Tennessee, 37403, USA
2 - University of Tennessee, Department of Ecology and Evolutionary Biology, 437 Hesler Biology Building, 1406 Circle Drive, Knoxville, Tennessee, 37996-1100, USA

Keywords:
hybrid plum Prunus Rosaceae.

Presentation Type: Oral Paper
Session: 44-10
Location: Salon G - Austin Grand Ballroom/Hilton
Date: Wednesday, August 17th, 2005
Time: 10:45 AM
Abstract ID:262