Sequence of the S10 cDNA from 'McIntosh' apple and a PCR-digestion identification method

An S-allele cDNA was cloned from pistils of 'McIntosh' apple (Malus xdomestica Borkh.). The allele, designated S-i in Japan and S-10 in Europe, is an S-RNase that is very similar (94%) to the S-3-RNase at the deduced amino acid sequence level. This allele can be detected by amplification using the polymerase chain reaction (PCR) and specific primers, followed by digestion with restriction enzyme EheI. The S-10 allele was discovered in 'Empire', 'Maypole', 'Shinano Red', 'Spencer', and 'Vista Bella'. The S-allele cDNAs sequenced to date are listed with their Japanese and European designations.