Guilliams, C. Matt , Baldwin, Bruce G. .
Phylogenetic Relationships of the Popcorn Flowers, Plagiobothrys (Boraginaceae), Inferred Using nrDNA (ITS) and cpDNA (trnL-trnF, rps16, 3' trnL).
Plagiobothrys (Boraginaceae) is morphologically and ecologically diverse, currently treated as comprising 89 minimum rank taxa of annual and perennial herbs. The genus is amphitropically distributed in the New World, with most taxa in western North America and approximately 29 in temperate South America. Plagiobothrys has been extensively studied morphologically, but has not been the subject of critical reappraisal using phylogenetic methods and DNA sequence data. Here we present the results of preliminary molecular phylogenetic analyses in Plagiobothrys, with a focus on Sect. Allocarya, a putative clade that appears to have largely diversified in vernal pool and wetland ecosystems in California, Oregon, and Baja California, Mexico. Preliminary phylogenetic analyses based on four non-coding regions (ITS, trnL-trnF intergenic spacer, rps16 intron, and 3' trnL intron) provide an intriguing first glimpse into possible evolutionary scenarios in the genus. These analyses reveal that Plagiobothrys is likely non-monophyletic, with Sect. Amsinckiopsis placed with Amsinckia and Sect. Sonnea with Cryptantha. Four of five recognized sections are recovered as monophyletic groups with strong support, including sect. Allocarya. Sect. Plagiobothrys, which contains some of the more common and widespread species of popcorn flowers (e.g., P. nothofulvus), is non-monophyletic. A few well-supported clades were resolved within Sect. Allocarya, although relationships among those clades are unresolved. This lack of phylogenetic structure at the base of section Allocarya is suggestive of rapid diversification, possibly with the development of vernal pool ecosystems in the California Floristic Province. Further studies will aim at examining genetic structure and ecological differentiation in one group of taxa in section Allocarya.
Log in to add this item to your schedule
1 - University of California, Berkeley, Department of Integrative Biology, University and Jepson Herbaria, 1001 Valley Life Sciences Bldg. #2465, Berkeley, California, 94720, USA
California Floristic Province.
Presentation Type: Oral Paper:Papers for Sections
Location: 552B/Convention Center
Date: Wednesday, August 4th, 2010
Time: 8:30 AM