EVALUATION OF DNA BASED TECHNIQUES FOR THE DETERMINATION OF SWEET CHERRY (PRUNUS AVIUM L.) SELF-INCOMPATIBILITY GENOTYPES

Sweet cherry carries a multi-allelic, gametophytic self-incompatibility gene, referred to as the S-locus. It is important for further research and orchard planning that the S-genotype of new cultivars is known before release. The aim of this study was to evaluate three published protocols for the determination of S-alleles of cherry cultivars grown at the Lenswood research station. The three methods involved the use of the polymerase chain reaction (PCR), multiple primer sets and some included restriction endonuclease digestion for the detection of S-alleles based on molecular weight. A modified CTAB method and two commercially available DNA isolation kits were evaluated for quality of DNA produced, cost and ease of use. A commercial kit used with a ball bearing crush of leaf material was found to be the most suitable protocol for extraction of cherry DNA, producing extracts of consistent high concentration and quality. PCR amplicons were separated on agarose or polyacrylamide gels. The S-alleles of thirty-seven cherry cultivars were determined using two of the primer sets without restriction digestions.