Correlation of ribonuclease zymograms and incompatibility genotypes in almond

Abstract

Proteins were extracted from styles of 29 self-incompatible cultivars of almond and separated using non-equilibrium pH gradient electro-focusing, and the gels were stained for ribonuclease activity. Mutually incompatible cultivars had similar banding patterns and, for the 24 cultivars already genotyped in France or California, the bands correlated well with the reported alleles. The band corresponding to S1 of the French labelling system was indistinguishable from that corresponding to Sb of the Californian labelling system, and a controlled cross confirmed that these alleles are identical. The band corresponding to the Californian Sa was distinct from the bands corresponding to French alleles and, to harmonise the allele labels, it was redesignated S5. The genotypes of five uncharacterised self-incompatible cultivars were inferred from zymograms as follows: ‘Desmayo Largueta’ and ‘Glorieta’, S1S5, ‘Masbovera’, S1S9, ‘Tarragones’, S2S9, and ‘Tokyo’, S6S7. The alleles designated S6 and S9 have not previously been reported. Nine self-compatible cultivars or selections were analysed, and each showed a band corresponding to an incompatibility allele as well as a common band; however, the correspondence of this common band to Sf, the allele for self-compatibility, is unproven.