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ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #346733

Research Project: Evaluation and Genetic Improvement of Woody Ornamental Landscape Plants for Disease and Pest Tolerance, Non-Invasiveness, and Ornamental Traits

Location: Floral and Nursery Plants Research

Title: Genetic diversity of Magnolia ashei characterized by SSR markers

Author
item Von Kohn, Christopher
item Conrad, Kevin
item Kramer, Matthew
item Pooler, Margaret

Submitted to: Conservation Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2018
Publication Date: 4/20/2018
Citation: Von Kohn, C.M., Conrad, K.P., Kramer, M.H., Pooler, M.R. 2018. Genetic diversity of Magnolia ashei characterized by SSR markers. Conservation Genetics. https://doi.org/10.1007/s10592-018-1065-8.

Interpretive Summary: The Ashe magnolia (Magnolia ashei) is a deciduous small tree most noted for its large 1-2 foot long leaves and fragrant creamy white flowers. Although the species is adapted to and used in landscapes in many parts of the U.S., it is endemic only to Northwest Florida where it is limited to ten counties growing on undisturbed bluffs and ravine banks. The populations are highly fragmented and are threatened by degradation of habitat, leading the species to be listed as threatened in the state of Florida. ARS scientists in Beltsville, MD collected samples from the wild populations of Ashe magnolia and used molecular techniques to determine the genetic diversity of these populations. Results from this study indicate that the populations are genetically distinct and contain substantial diversity within each population. This information will be used to develop long-term conservation strategies to protect the species both in the wild and in cultivation.

Technical Abstract: The Ashe magnolia (Magnolia ashei) is a deciduous small tree most noted for its large 1-2 foot long leaves and fragrant creamy white flowers. Although the species is adapted to and used in landscapes in many parts of the U.S., it is endemic only to Northwest Florida where it is limited to ten counties growing on undisturbed bluffs and ravine banks. The populations are highly fragmented and are threatened by degradation of habitat, leading the species to be listed as threatened in the state of Florida. SSR markers were developed to determine the genetic diversity of wild populations of M. ashei in order to guide long-term conservation strategies. 18 marker loci identified a total of 82 alleles that were used to characterize allelic diversity of M. ashei from 11 wild populations, 14 cultivated sources, five accessions of M. macrophylla, and three interspecific hybrids. Results indicated a higher than expected level of heterozygosity within populations, and a clear distinction among populations. Clustering of individuals was similar using STRUCTURE, UPGMA, or PCA, indicating that despite relatively small sample sizes, our analysis is an accurate reflection of the diversity among and relationships between these populations.