S-allele constitution of hexaploid European plum cultivars
European plum (Prunus domestica) is an important fruit crop in Central Europe with a complex hexaploid genome of unknown origin. The characterization of the S-locus of 17 economically important European plum cultivars was carried out. To characterize the length polymorphism for first and second introns, the PaConsI and EM-PC primer pairs were used. Altogether, 18 different alleles were identified, of which 11 S-RNase alleles were first detected. To confirm S-allele identity, partial S-RNase sequences were determined and blasted on the GenBank database. Partial S-haplotype-specific F-box alleles were also cloned and sequenced. Several trans-specific alleles were detected and their phylogenetic analysis and Tajima's D test showed the rate of evolution dramatically accelerates when allele specificity is modified by fixed amino acid replacements. A total of 17 different S-genotypes were assigned, so the discrimination of all assayed plum cultivars was successful based on their unique S-genotypes. Cross-incompatible cultivars were not found. Our analysis is continued to identify mutations in the S-locus genes that might be responsible for the transition from a self-incompatible to a self-compatible phenotype in a hexaploid species.
Makovics-Zsohár, N., Hegedűs, A. and Halász, J. (2019). S-allele constitution of hexaploid European plum cultivars. Acta Hortic. 1231, 151-156
Prunus domestica, evolution, intron length polymorphism, S-genotype, S-RNase