Analysis of Genetic Diversity and Population Structure for the Native Tree Viburnum rufidulum Occurring in Kentucky and Tennessee

Abstract

<jats:p><jats:italic>Viburnum rufidulum</jats:italic> is a deciduous tree native to North America that has four-season appeal, which provides commercial horticultural value. In addition, the plant has unique and attractive red pubescence on leaf buds and petioles, common to no other <jats:italic>Viburnum</jats:italic> species. As habitat undergoes development and subsequent fragmentation of native plant populations, it is important to have baseline genetic information for this species. Little is known about the genetic diversity within populations of <jats:italic>V. rufidulum.</jats:italic> In this study, seven microsatellite loci were used to measure genetic diversity, population structure, and gene flow of 235 <jats:italic>V. rufidulum</jats:italic> trees collected from 17 locations in Kentucky and Tennessee. The genotype data were used to infer population genetic structure using the program InStruct and to construct an unweighted pair group method with arithmetic mean dendrogram. A single population was indicated by the program InStruct and the dendrogram clustered the locations into two groups; however, little bootstrap support was evident. Observed and expected heterozygosity were 0.49 and 0.78, respectively. Low-to-moderate genetic differentiation (<jats:italic>F</jats:italic><jats:sub>ST</jats:sub> = 0.06) with evidence of gene flow (N<jats:sub>m</jats:sub> = 4.82) was observed among 17 populations of <jats:italic>V. rufidulum.</jats:italic> A significant level of genetic diversity was evident among <jats:italic>V. rufidulum</jats:italic> populations with most of the genetic variations among individual trees (86.37%) rather than among populations (13.63%), and a Mantel test revealed significant correlation between genetic and geographical distance (<jats:italic>r</jats:italic> = 0.091, <jats:italic>P</jats:italic> = 0.001). The microsatellites developed herein provide an initial assessment or a baseline of genetic diversity for <jats:italic>V. rufidulum</jats:italic> in a limited area of the southeastern region of the United States. The markers are a genetic resource and can be of assistance in breeding programs, germplasm assessment, and future studies of <jats:italic>V. rufidulum</jats:italic> populations, as this is the first study to provide genetic diversity data for this native species.</jats:p>

Development and Characterization of 15 Novel Genomic SSRs for Viburnum farreri

“…gSSRs were also developed for safflower with similar methods to our study, and those markers also displayed cross-transferability [ 48 ]. A preliminary study of cross-transferability of Viburnum species gSSRs developed in [ 41 , 42 ] was completed and indicated wide-transferability was possible [ 44 ]. Therefore, the markers developed in this study should have some cross-transfer success with other Viburnum species and help fill in missing data from gaps left by the previously developed markers.…”

“…gSSRs have been developed for four of the~163 species of Viburnum including V. dilatatum [41], a member of the Succotinus subclade, V. rufidulum [42], a member of the Lentago subclade, and V. triphyllum and V. pichinchense [43], which are members of the Oreinotinus subclade [21]. These gSSRs were developed for species/cultivar identification as well as investigation of population genetic diversity.…”

“…They represent species in three of the larger clades ( Laminotinus, Valvatotinus , and Porphyrotinus , respectively), leaving only Crenotinus unrepresented. A preliminary study on the cross-transferability of the markers developed for V. dilatatum [ 41 ] and V. rufidulum [ 42 ] was conducted and demonstrated wide, but not complete transferability of these gSSRs [ 44 ]. Inclusion of markers for V. farreri, a member of the Crenotinus clade and the Solenotinus subclade, would provide more extensive coverage of species across the entire Viburnum genus.…”

Habitat fragmentation influences genetic diversity and differentiation: Fine‐scale population structure ofCercis canadensis(eastern redbud)

“…( F ST = 0.04), and Viburnum rufidulum Raf. ( F ST = 0.06) (Dean et al, 2015; Duan et al, 2015; Hadziabdic et al, 2012; Hamrick et al, 1992; Hardesty, Dick, Kremer, Hubbell, & Bermingham, 2005). Similar to findings of this report, understory temperate trees species, Sorbus torminalis L. (Crantz) (wild service tree, F ST = 0.17) and Cladrastis kentukea (Dum.…”

Genetic diversity in North American Cercis Canadensis reveals an ancient population bottleneck that originated after the last glacial maximum

“…Populations of Viburnum rufidulum Raf. 89 and Cornus florida L. 68 are temperate tree species that are widely distributed in the southeastern U.S. and have low genetic differentiation with weak population structures. Across populations of V. rufidulum and C. florida , high levels of gene flow via pollen and seed dispersal may have reduced genetic variability 75 , 89 .…”