Diversity and spatial structure of clones inVaccinium uliginosumpopulations

Abstract

In Belgium, a total of three Vaccinium species with a shrub or dwarf shrub growth form can be found: Vaccinium myrtillus L., Vaccinium vitis-idaea L., and Vaccinium uliginosum L. Vaccinium uliginosum is the only one of these for which the extent of clonality is unknown. Therefore, the clonal structure of two V. uliginosum populations was inferred from random amplified polymorphic DNA (RAPD) markers. Among the 47 sampled patches, 61 clones were identified. The mean values of the number of clones divided by the number of samples (G/N), the Simpson's index (D), and the genotypic evenness (E) were 0.28, 0.95, and 0.96, respectively. Vaccinium uliginosum exhibited a typical phalanx growth strategy that resulted in structured populations at the ramet level, that is, ramets belonging to the same clone were closely associated and formed distinct clumps. However, at the clone level, populations were not structured, that is, genetic distances between pairs of clones were not correlated with the spatial distances between the clones within a population. Genetic diversity was as high as that in nonclonal species (mean value of Shannon's diversity index (Ho) = 0.647). In accord with the life history traits of V. uliginosum (long-lived species with a mixed breeding system and potentially high seed dispersal), most of the genetic variation was found within populations.Key words: genetic diversity, genetic structure, seedling recruitment, vegetative propagation, Ericaceae.