Characterization of Eight Novel Microsatellite Markers from Viburnum rufidulum

Viburnum rufidulum resides in the Adoxaceae and is one of the fifteen species of shrubs within the genus that are native to the United States. Viburnum rufidulum can be distinguished from the closely related species V. prunifolium by the reddish pubescent petioles, leaf buds, and undersides of leaves. The attractive red pubescence gives V. rufidulum its common name of 'Rusty Blackhaw'. Prior to this study, genetic diversity of the species has not been investigated. We report the results of a small insert GT-enriched genomic microsatellite library constructed from genomic DNA of V. rufidulum. Eight microsatellite loci were characterized and have successfully amplified DNA from 44 samples of V. rufidulum that were collected from individuals growing in close proximity to each other at Worthington Cemetery located in Oak Ridge, TN. Four–to- seventeen alleles were identified per locus, and the mean polymorphic information (PIC) content was 0.68.  The range for allelic richness was 4-14 and gene diversity was 0.65–0.89. The inbreeding coefficient (Fis) mean for all loci was 0.4 and observed heterozygosity mean (H_o) was 0.44, which deviates from the expected heterozygosity (H_e) average of 0.73. The program STRUCTURE 2.3.4 was able to discern two discreet populations within the samples. These microsatellite loci also exhibit high cross-species transferability to other Viburnum species and genera in the Adoxaceae.  The loci discovered in this study are expected to be useful in population genetic studies of this plant, and applicable to any population throughout the natural range of V. rufidulum. Moreover, these markers are expected to have utility in breeding programs, and also in refining and defining the phylogenetic relationship of V. rufidulum to other species within the genus, and to other genera within the Adoxaceae.