GENETIC DIFFERENTIATION OF DIPLOID BLUEBERRY, VACCINIUM SECT CYANOCOCCUS (ERICACEAE)

The most dissected taxonomic treatment of Vaccinium section Cyanococcu s, generated by Camp in 1945, recognized nine diploid (2n = 24) taxa. More recently, Vander Kloet recognized six taxa nesting the two hillsi de blueberries and the three highbush blueberries, respectively. Where as previous taxonomic treatments have been based primarily upon morpho logical data, field studies, chromosome counts, and crossability, the present study employs allozyme data to assess genetic relationships of representative diploid blueberry populations. Starch gel electrophore sis was conducted on population samples obtained from 25 sites identif ied in an extensive field survey of this endemic North American sectio n. Data were collected at 11 polymorphic loci previously observed to h ave high taxonomic information content. Data were analyzed to obtain s imilarity, as well as standard measures of population genetic structur e. Five genetic lineages were discriminated; these were supported by h ighly disparate allelic frequencies. Conspecific populations were undi fferentiated, with distribution of genetic variation similar to that d escribed for other predominantly outcrossing species. In conjunction w ith patterns of morphological variation, this study supports the recog nition of seven species: two highbush species, V. corymbosum and V. el liottii, and five lowbush species, V. boreale, V. darrowii, V. myrtill oides, V. pallidum, and V. tenellum.