GENETIC RELATEDNESS AMONG RABBITEYE BLUEBERRY (VACCINIUM-ASHEI) CULTIVARS DETERMINED BY DNA AMPLIFICATION USING SINGLE PRIMERS OF ARBITRARYSEQUENCE

Most improved cultivars of commercially important hexaploid rabbiteye blueberry were developed from only four native selections collected fr om the wild; thus, many cultivars are closely related by lineage. The consanguinity among major cultivars is a potential problem, as the rab biteye blueberries are highly self-incompatible natural outcrossers wi th potential inbreeding depression. We investigated the extent of gene tic relatedness among 15 improved cultivars and four wild selections b y the technique of random amplified polymorphic DNA, also referred to as arbitrarily primed polymerase chain reaction. Single decanucleotide s of arbitrary sequence revealed polymorphism among cultivars and wild selections. Genetic distances were estimated based on the amount of b and sharing. Cluster analysis of genetic distance estimates tended to group siblings with each other and with one or both parents. The avera ge genetic distance between improved cultivars decreased relative to t he four wild parental selections, which might indicate progression tow ards inbreeding. The significance of increased genetic relatedness amo ng the improved cultivars of rabbiteye blueberry and the application o f molecular methods in breeding and commercial cultivation is discusse d.