Re-examination of (in)compatibility genotypes of two John Innes self-compatible sweet cherry selections

Abstract 

The (in)compatibility genotypes of two self-compatible sweet cherry selections, JI 2420 and JI 2434, originating from the John Innes Institute were re-examined. The selections and seedlings derived from them were analysed for stylar ribonucleases, which are known to correlate with S alleles, and the outcome of test crosses was recorded. JI 2420, which had been reported previously as S ₃ S ₄ ", where " indicates loss of pollen activity, was deduced to have the genotype S ₄ S ₄ ’. For JI 2434, which had been reported previously as S ₃ S ₄ ⁰ , S ₃ S ₃ ⁰ or S ₃ S ₃ ", where ⁰ indicates loss of pollen and stylar activity, two different clones were identified. One, at East Malling, was deduced to be S ₃ "S ₄ ; the other, at Ahrensburg, appeared to be S ₃ S ₃ " or S ₃ S ₃ ⁰ .