Abstract Detail

Population Genetics

Swift, Joel [1], Lindsay, Denise [2], Edwards, Christy [1], Jung, Michael [2], Lance, Richard [2].

The relative effects of geographic distribution on patterns of genetic structure in two Agave (Agavaceae) species with similar life history strategies.

Many factors may affect the structuring of genetic variation in plants, including their pollinators, seed dispersers, and the continuity of their geographic ranges. In this study we examined the relative effects of these three factors in structuring genetic variation Agave palmeri (diploid) and Agave parryi (autotetraploid), which share the same pollinator and seed dispersal mechanism, but differ in the continuity of their geographic distributions. Both of these species are thought to be predominantly bat pollinated and wind dispersed, which because they allow long-distance migration are generally thought to have the effect of reducing population differentiation. However, the two species differ in their distributions, which may have contrasting effects on the structuring of genetic variation; A. palmeri has a widespread distribution throughout lower elevation areas in northern Mexico, southern Arizona, and New Mexico, whereas A. parryi is more restricted in its distribution and is found only in higher elevations on sky islands in central Arizona, southwestern New Mexico, and the highlands of Mexico. In this study, we examined whether the patchy distribution of A. parryi has caused stronger structuring of genetic variation relative to A. palmeri, or whether pollinators and seed dispersal reduces these effects. We sampled 12 populations of each of the two Agave species from Arizona and New Mexico , genotyped individuals at 9 microsatellite loci, and analyzed patterns of genetic diversity and structure. Results show genetic structure in populations of A. parryi, forming 3 distinct clusters that correspond to geographic locations. Since genetic variation is structured only in A. parryi, we can conclude that the patchy distribution limits gene flow in A. parryii even though pollen and seeds should be able to allow genetic material to travel long distances. Results indicate that the continuity of the geographic distribution of a species has important effects population processes.

1 - Missouri Botanical Garden, Center for Conservation and Sustainable Development, PO Box 299, St. Louis, MO, 63166, USA
2 - U.S. Army Engineer Research and Developement Center, Environmental Laboratory, 3909 Halls Ferry Road , Vicksburg, MS, 39180, USA

Keywords:
Agave palmeri
Agave parryi
Distribution
Genetic variation
microsatellites.

Presentation Type: Poster
Session: P, Population Genetics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPG004
Abstract ID:428
Candidate for Awards:None