Rupert Barneby and his legume legacy
Allphin, Loreen .
The history and future of population genetic research in the conservation of rare Astragalus species.
Astragalus (Fabaceae) is complex genus, consisting of 650 North American taxa, that has its center of distribution and diversity in the western United States, notably the Great Basin of Utah and Nevada, California, and northern Arizona. This genus is known for its exceptionally high rates of diversification, speciation, and endemism. Many species in the genus persist in small, highly restricted populations and are endemic to particular geologic formations or geographic regions. A survey of the current population genetic research in Astragalus has revealed some consistent patterns. First, most of the rare, endemic taxa in Astragalus occur in small, isolated populations with low levels of genetic variation within and among populations. In contrast, widespread congeners exhibit higher levels of genetic diversity within and among populations. The literature has elucidated the need for further research to determine whether low levels of genetic diversity in endemic taxa are associated with reduced fitness, or are a consequence of their recent evolutionary origin. DNA fingerprinting techniques such as SSRs, ISSRs, and AFLPs have the potential to resolve greater genetic variability and allow for more thorough population genetic studies than allozymes. Most of the conservation and population genetic studies in Astragalus assume a well supported classification for the taxon or group studied. However, despite the solid taxonomic foundation provided by Barneby, there are still new discoveries to be made and complex taxonomic issues to resolve in the genus. Therefore, it is important that future population genetic studies in Astragalus also include rigorous examinations of morphological variation at the population level.
1 - Brigham Young University, Department of Integrative Biology, P.O. Box 5181, Provo, Utah, 84602, USA
Presentation Type: Symposium
Location: Magpie (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 4:00 PM