| Abstract Detail
Population Genetics Wenzel, Aaron [1], Wolfe, Andrea D. [2]. Population genetics, systematics, and polyploidy in Penstemon caespitosus (Plantaginaceae) from Utah. Penstemon caespitosus is one of several widespread species in section Ericopsis of Penstemon, with a range stretching from Utah into western Colorado and southern Wyoming. The species consists of three varieties that have been described based on morphological variations existing throughout its range. However, no study has considered the varieties of P. caespitosus using molecular markers. In addition, a recent flow cytometry study found that one of the varieties, desertipicti from southwest Utah and northern Arizona, is a tetraploid (4x=4n=32), differing from diploid varieties caespitosus and perbrevis (2x=2n=16). The nature of the polyploidy of var. desertipicti (i.e., autopolyploidy vs. allopollyploidy) is not known. The aim of this study was to use microsatellite markers in a population genetics study of the varieties of P. caespitosus in Utah in order to investigate patterns of population genetic diversity, population differentiation, and polyploidy in var. desertipicti. Seven microsatellite loci were used for 9 populations of P. caespitosus collected in Utah (222 total individuals). Results indicated varying levels of genetic diversity in the three varieties, with var. caespitosus consistently showing lower measures of allelic diversity and heterozygosity. Variety desertipicti, comparatively, had the highest values of these measures, with total heterozygosity over all loci equaling 89%. Analysis of molecular variance found that the majority of variation (88%) occurred within populations, suggestive of strong population genetic structuring. This was corroborated in high and significant pairwise PhiPT values (averaged PhiPT=0.124). Varieties perbrevis and desertipicti, however, exhibited a closer relationship as measured by PhiPT values and three clustering analyses (PCoA, Neighbor joining tree, and STRUCTURE). These results indicate that the northern var. caespitosus may be experiencing isolation from the other two varieties. Variety desertipicti contains many unique alleles that are not present in either the two varieties of P. caespitosus or P. linarioides subsp. sileri (a related species from southern Utah), a pattern consistent with an allotetraploid origin. Variety desertipicti did, however, share a substantial percentage of alleles with var. perbrevis (17% of total alleles), and the two varieties cluster close to one another in all analyses. It is concluded that var. perbrevis is mostly likely one of the parent progenitors of var. desertipicti; P. linarioides subsp. sileri can be neither confirmed nor rejected as the other progenitor, so other species (especially P. thompsoniae) should be considered in future studies.
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1 - Ohio State University, EEOB, 318 W. 12th Ave, Columbus, Ohio, 43210, United States
2 - Ohio State University, Department Of Ecology, Evolution, And Organismal Biology, 318 W. 12th Avenue, COLUMBUS, OH, 43210-1293, USA
Keywords:
Penstemon
Microsatellite
polyploidy
population genetics
Utah
Systematics.
Presentation Type: Oral Paper
Session: 39, Population Genetics
Location: 201/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 8:30 AM
Number: 39003
Abstract ID:611
Candidate for Awards:None |
