Submitted to: Journal of American Society of Horticulture Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 27, 1996
Publication Date: N/A
Interpretive Summary: In recent years breeders have released several blueberry cultivars comprised of diverse species and from widely different geographical areas. Like in most perennial, outcrossing plant species, breeding programs and genetic analysis in blueberry have been constrained by paucity of genetic markers. The recent advancement of the genetic assay termed RAPD (randomly amplified polymorphic DNA) has furnished an efficient means to produce large numbers of molecular markers that permits the estimations of relatedness among breeding materials and distinguishes cultivars. In the present study the objectives were to identify polymorphic RAPD and SSR (simple sequence repeat) markers that would be useful for distinguishing blueberry cultivars, and to use the DNA markers to examine genetic diversity among twelve northern and three southern highbush blueberry (V. corymbosum) cultivars, two rabbiteye (V. ashei) cultivars and one southern evergreen lowbush (V.darrowi) selection. Analysis of relative genetic distance between cultivars is shown to be compatible with known pedigree data. The present study provides vital information which can be used by nurseries to confirm the identity of their stock plants and by breeders to select the most diverse germplasm for their breeding programs.
Technical Abstract: Twelve northern and three southern highbush blueberry cultivars (Vaccinium corymbosum Linnaeus), two rabbiteye blueberry cultivars (V. ashei Reade) and one southern lowbush (V. darrowi Camp) selection, were examined using ten 10-base (randomly amplified polymorphic DNA; RAPD) and five 17-18-base (simple sequence repeat; SSR) primers in polymerase chain reactions (PCR). Various levels of polymorphism were detected that readily distinguished the seventeen blueberry cultivars and one selection. Calculation of dissimilarity values based on 62 and 41 distinct RAPD and SSR bands (respectively) revealed that among the V. corymbosum cultivars `Weymouth' was the most divergent, while the cultivars `Bluecrop', `Gulfcoast', `Duke', `Blueray', `Cooper', `Nelson' and `Bluegold' were the least divergent. The V. ashei cultivars and V. darrowi selection grouped out separately from the V. corymbosum cultivars as expected. This study suggests that in order to obtain an accurate determination of genetic relatedness, a large number of polymorphic fragments should be analyzed (approximately 100). Presumably, this is due to a larger part of the blueberry genome being represented with the examination of more RAPD markers.