Saunders, N. , Sipes, Sedonia .
A Molecular Phylogeny of Abronia Juss.and Tripterocalyx (Torr.) Hook (Nyctaginaceae) with notes on the generic revision.
Abronia Juss.is a genus of 20 sand and gypsum specialists found in maritime, montane and desert habitats of western North America. Tripterocalyx (Torr.) Hook includes four species limited to the Great Basin Desert. All are characterized by small population sizes, adaptation to a highly specific and uncommon habitat, and tolerance of environmental extremes. The genera are thought to have only recently radiated into the North American deserts, and many taxa are thought to be actively speciating. Modern treatments rely on highly variable morphological characters, soil preferences, or geographic location for species delineation, resulting in an unstable taxonomy. Treatments have variously collapsed Tripterocalyx within Abronia with others holding them distinct. Although generic hybrids are unknown, many Abronia readily hybridize in sympatry. We sampled 116 populations, representing 20 recognized Abronia, four Tripterocalyx and four outgroup species from within the Nyctaginaceae. We sequenced the nuclear ribosomal intergenic spacer, using primers ITS1 and ITS4, as well as three chloroplast regions (trnS-trnG-trnG, trnF-trnDT, and rpoB-trnCR) and performed a phylogenetic analysis to produce a maximum likelihood-bootstrap tree. Our analysis supports the monophyly of Abronia and Tripterocalyx. Within Abronia, there are two well supported maritime clades, with Abronia latifolia distinct from the other maritime species with which it grows in sympatry and Abronia alpina sister to all other Abronia. The third clade includes desert and montane species, and our data supports a cold desert and a hot desert grouping. We provide preliminary information on a taxonomic revision of the genera and include information about a species within Abronia, believed to be new to science.
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1 - Southern Illinois Univeristy, Plant Biology, 1125 Lincoln Drive, Suite 420, Carbondale, IL, 62901-6509, USA
2 - Southern Illinois University, 1125 Lincoln Drive, Mail Code 6509, Carbondale, IL, 62901, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 2:00 PM