Kramer, Andrea T. , Fant, Jeremie , Ashley, MV .
Pollinators and their influence on population genetic structure in three widespread Penstemon species(Plantaginaceae).
How do landscape features interact with plant life history traits, such as reproductive biology and dispersal capacity, to influence population genetic structure and future evolutionary potential of plant species? The answer varies by species, and understanding broader patterns requires a comprehensive approach. We identify population genetic divergence in three species of Penstemon (Plantaginaceae) that have different pollination syndromes (bee and hummingbird) but share key life history traits (e.g. gravity-dispersed seeds) and are similarly distributed throughout the Great Basin region of the western United States. The Great Basin, with its repeating series of over 100 mountain ranges separated by arid basins, is an ideal landscape to compare the interaction of landscape and life history in isolating populations of different species. We utilized eight highly polymorphic microsatellite loci to identify the neutral population genetic structure between populations within and among mountain ranges for eight populations of P. deustus and ten populations each of P. pachyphyllus and P. rostriflorus. We found significant genetic structure in all three species, ranging from high structure and low gene flow in the bee-pollinated P. pachyphyllus (FST = 0.1896, seven genetic clusters identified) and much lower structure and higher gene flow in the hummingbird-pollinated P. rostriflorus (FST = 0.0638, three genetic clusters identified). In examining these otherwise similar Penstemon species with different pollination syndromes, we demonstrated that pollinators have a significant effect on gene flow and, hence, on population genetic structure.
Our results can be used to guide ecological restoration efforts for our study species and those that share similar characteristics found throughout the unique landscape of the Great Basin region. Findings of high genetic diversity and significant population genetic structure in all three species support ongoing efforts to bank seeds of multiple populations to store genetic diversity for future restoration and research efforts (DeBolt and Spurrier, 2004). Our findings of significant genetic structure also caution against broad-scale movement and mixing of populations for restoration purposes. Given the greater among-population gene flow identified in the hummingbird pollinated P. rostriflorus, the large scale movement of seeds to restore populations of hummingbird-pollinated species may pose less risk to the success of a restoration than bee-pollinated species.
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1 - Botanic Garden Conservation International
2 - Chicago Botanic Garden, Plant Science and Conservation, 1000 Lake Cook Road, Glencoe, IL, 60022, USA
3 - University of Illinois at Chicago, Biological Sciences, 845 W. Taylor St., Chicago, IL, 60607, USA
Presentation Type: Oral Paper:Papers for Topics
Location: 553A/Convention Center
Date: Monday, August 2nd, 2010
Time: 1:30 PM