Wide Cross-Transferability of SSR Loci from Three Viburnum Species

Viburnum is a large genus of woody shrubs comprised of approximately 160 species and a member of the Adoxaceae.  In the past, Viburnum was a member of the Caprifoliaceae, but the genus has undergone myriad reclassifications based on both molecular and morphological studies.  Fifty Viburnum species and five related genera (Adoxa moschatellina, Sambucus nigra, S.canadensis, Lonicera japonica and Weigela florida) were included in this study.  Thirty-three SSR markers were developed from the following Viburnum species: V. dilatatum, V. farreri and V. rufidulum and were utilized to characterize and assess the relationships between the various taxa in Adoxaceae and Caprifoliaceae.  Cross transferability of the loci was analyzed and the number of alleles per locus ranged four to thirty-nine. The polymorphic information content ranged from 0.42 to 0.97.  From the group of thirty-three SSR markers, three genomic microsatellite loci were selected and used to construct a phylogenetic tree.  The sequence alignments indicated well preserved primer sites throughout all taxa analyzed, as indicated by the successful cross transferability among many Viburnum as well as limited amplification to other genera.  However reconstruction of a well-supported phylogenetic tree was not possible.  Despite the inability to predict phylogeny this set of SSR markers are expected to have utility in future genetic and population studies, marker assisted selection and breeding programs as well.