S-GENOTYPING OF HUNGARIAN AND EASTERN EUROPEAN APRICOTS
Apricot (Prunus armeniaca L.) shows gametophytic self-incompatibility, controlled by a single locus with eight described allelic variants. An allele for self-compatibility (SC) allows self-fertilisation, whereas seven alleles for self-incompatibility (S1-S7) arrest pollen tube growth if the same allele is present both in pollen and pistil. Twenty-three apricot accessions were analysed for stylar ribonucleases by non-equilibrium pH gradient electrofocusing (NEpHGE) and by S-haplotype-related PCR amplification. NEpHGE revealed 13 bands from cultivars not genotyped previously, corresponding to putative new S-alleles, provisionally labelled as SA-SN. Three previously-described self-incompatibility alleles, S1, S4 and S7, seem, possibly, to be present also in these cultivars, but this must be confirmed by test pollinations. Alleles S3, S5 and S6 were not available, but even if three other bands were found to be identical with any of the remaining 10 alleles in the future, seven new S-alleles were found in apricot. The S-RNase isoenzyme pattern showed a good correlation with the PCR data obtained by cherry consensus primers. From a theoretical point of view, this provided further support to the hypothesis that the S-RNase gene family within the Rosaceae has been highly conserved in the course of evolution. A new set of degenerate primers (EM) detected each tested S-allele, thereby confirming further the S-genotypes assigned by combining the results of protein and DNA-based methods. This is the first study providing evidence that, similarly to other Prunus species, the S-locus of apricot is more variable than was previously considered.
Pedryc, A., Halasz, J. and Hegedus, A. (2006). S-GENOTYPING OF HUNGARIAN AND EASTERN EUROPEAN APRICOTS. Acta Hortic. 717, 217-224
non-equilibrium pH gradient electro-focusing, PCR, Prunus armeniaca, S-allele, self-incompatibility, S-RNase