Comparative Chromosome Morphology of Diploid Vaccinium Species1

Abstract

Abstract Representative clones of the diploid (2n = 24) members of the subgenus Cyanococcus (true or cluster-fruited blueberries) of Vaccinium, as well as V. crassifolium Andr. (Herpothamnus subgenus) and V. macrocarpon Ait. (Oxycoccus subgenus) were studied cytologically. They were collected from localities ranging from Florida to Nova Scotia and varied markedly in their gross morphology. The length of the total chromosome complement and the ratio of the longest to the shortest chromosome of each clone were determined. While a range of significant differences were demonstrated among clones, these differences were considered to be of minimal importance in species identification. A single idiogram can represent the karyotypes of all of the diploid Cyanococcus species examined. A tentative idiogram of their haploid complement consisted of 2 long and 2 short chromosomes and 8 of intermediate length, one of which was satellited. All had median or submedian centromeres. The karyotypic stability of the diploid Vaccinium species leads to the conclusion that the broad variability in morphology and adaptation which they exhibit has been principally genic in origin.