Document Type
Article
Publication Date
2022
DOI
10.2179/0008-7475.87.1.129
Publication Title
Castanea
Volume
87
Issue
1
Pages
129-146
Abstract
Chamaecrista fasciculata is a widely distributed, phenotypically variable species in the eastern U.S. Whereas studies have demonstrated genetic structure and local adaptation in northern areas of its distribution, there has been no comparison of genetic variability among populations at the southern extent where phenotypic variation is more complex. We characterized genetic variation at 14 microsatellite loci for populations in Mississippi and Alabama and compared this to variation in a phenotypic trait, leaf pubescence. Geographic distance, climatic variables, and elevation were evaluated as factors to explain the observed patterns of genetic diversity. A significant amount of variation (19%) resided among populations, but most variation (68%) was among individuals. Assignment of individuals into genetic groups suggests two primary clusters, but these groups are not concordant with known geographical or ecological breaks, nor phenotypic variants. Genetic structure at a regional scale can be characterized as isolation by distance, while environmental factors may play a secondary role in limiting gene flow at local scales. Mean population FST is strongly associated with allelic diversity and heterozygosity, suggesting that genetic drift influences population variation. Despite the presence of genetic and phenotypic variation in southern populations of C. fasciculata, the lack of concordant patterns between these types of variation indicate that they are not driven by the same factors. This study demonstrates how local factors differentially influence the maintenance of intraspecific variation and suggest the southern distributional range is an active area of evolution for C. fasciculata.
Rights
© 2022 Southern Appalachian Botanical Society.
Included with the kind written permission of the copyright holder.
Data Availability
Article states: "Microsatellite genotypes are deposited in Dryad (https://doi.org/10.5061/dryad.zw3r2289c)." [In Materials and Methods section]
Original Publication Citation
Nobarinezhad, M. H., & Wallace, L. E. (2022). Determinants of population genetic structure in Chamaecrista fasciculata (Michx.) Greene (Fabaceae) in the southeastern United States. Castanea, 87(1), 129-146.
Repository Citation
Nobarinezhad, Mahboubeh Hosseinalizadeh and Wallace, Lisa E., "Determinants of Population Genetic Structure in Chamaecrista fasciculata (Michx.) Greene (Fabaceae) in the Southeastern United States" (2022). Biological Sciences Faculty Publications. 484.
https://digitalcommons.odu.edu/biology_fac_pubs/484
ORCID
0000-0002-2280-1250 (Nobarinezhad)
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