Abstract Detail

Population Genetics

Culley, Theresa [1], Huebner, Cynthia [2].

Genetic Variation and Patterns of Spread Within Populations of Invasive Japanese Stiltgrass, Microstegium vimineum (Poaceae).

Japanese stiltgrass (Microstegium vimineum) is now widely recognized as an invasive species that is rapidly spreading into disturbed sites within natural areas and along roadsides, hiking paths, and waterways in the eastern United States. Despite increased concern about this species, scientists still do not have a clear understanding of how the plant spreads. To answer this question, 17 microsatellite markers were used to analyze nine populations of M. vimineum located across a moisture gradient within two regions (Allegheny Plateau and the Ridge and Valley) in West Virginia, USA. Within each population, three stages of potential spread were represented: along the roadside ("Roadside"); scattered within the adjoining forest interior ("Interior"), and large coalescing colonies spreading within the forest ("Coalescing"). We quantified levels of genetic diversity within each population, and also compared multilocus genotypes among the three groups (Roadside, Interior, Coalescing) within each population to determine the number of genets. Populations generally exhibited low to moderate levels of genetic variation (A = 1.29-5.47; Ho = 0.232-0.348; P = 52.9%-100%) with substantial genetic differentiation among populations (Fst = 0.428). Comparison of multilocus genotypes revealed that the same genotype can occur in more than one population but typically in populations located geographically close to one another. Within a given population, the same multilocus genotype was generally the most common in all of the three groups (Roadside, Interior, Coalescing), but with the largest proportion of the genotype typically found within the Roadside samples. With few exceptions, the Roadside samples also contained the largest number of multilocus genotypes. We are now continuing to examine patterns of spread within each population using parentage analysis of the different groups to determine if Interior and Coalescing plants originate from the Roadside. Overall, it appears that the spread of M. vimineum is not limited by a lack or scarcity of genetic variation within and among populations, despite its status as an introduced species in the United States and the potential for genetic bottlenecks.

Broader Impacts:

1 - University of Cincinnati, Department of Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221-0006, USA
2 - Northern Research Station, United States Forest Service, United States Department of Agriculture, 180 Canfield St., Morgantown, WV, 26505, USA

Keywords:
Japanese Stiltgrass
invasive species
genetic diversity
multilocus genotypes.

Presentation Type: Oral Paper:Papers for Topics
Session: 40
Location: Marlborough B/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 11:00 AM
Number: 40009
Abstract ID:678
Candidate for Awards:None