Molecular Markers for Self-compatibility in Japanese Apricot (Prunus mume)

Self-compatible cultivars of Japanese apricot ( Prunus mume Sieb. et Zucc.) have a horticultural advantage over self-incompatible ones because no pollinizer is required. Self-incompatibility is gametophytic, as in other Prunus species. We searched for molecular markers to identify self-compatible cultivars based on the information about S -ribonucleases ( S -RNases) of other Prunus species. Total DNA isolated from five self-incompatible and six self-compatible cultivars were PCR-amplified by oligonucleotide primers designed from conserved regions of Prunus S -RNases. Self-compatible cultivars exhibited a common band of ≈1.5 kbp. Self-compatible cultivars also showed a common band of ≈12.1 kbp when genomic DNA digested with Hin dIII was probed with the cDNA encoding S 2 -RNase of sweet cherry ( Prunus avium L.). These results suggest that self-compatible cultivars of Japanese apricot have a common S -RNase allele that can be used as a molecular marker for self-compatibility.