Primers amplifying a range of Prunus S-alleles

Although various consensus polymerase chain reaction (PCR) primers have been reported for identifying Prunus S-alleles, they have been developed from and optimized on a limited set of alleles, which may limit their applicability to a broader allele range. To develop a primer set for use across the genus, degenerate consensus primers were designed from conserved regions of 27 S-RNase sequences available from five Prunus species. The primers were tested in 15 previously genotyped cultivars of cherry, almond and apricot, representing alleles S-1 to S-6 in each crop and also S-c in apricot. Comparisons were made with previously published primers tested in the same 15 cultivars under reported reaction conditions. The new primers generated an amplification product for each of the 19 S-alleles whereas those previously available amplified no more than 14. The primers will be useful for genotyping and genetic studies in cultivars and wild populations.