Rahemi, A., Gradziel T.M., Chaparro J.X., Folta, K.M., Taghavi, T., Fatahi, R., Ebadi, A. and Hassani, D. 2015. Phylogenetic relationships among the first and second introns of selected Prunus S-RNase genes. Can. J. Plant Sci. 95: 1145-1154. To identify and evaluate self-incompatible alleles in almonds and related germplasm, DNA from 15 Prunus species was amplified using two degenerate consensus primer pairs flanking first and second S-locus introns (PaConsI-FD EM-Pc1ConsRD and EM-Pc2ConsFD EM-Pc3ConsRD). Twenty-eight amplified PCR products were analyzed by automated sequencer capillary electrophoresis. Sequenced fragments were aligned against available Prunus S-locus sequences in the National Center for Biotechnology Information and S-alleles identities were determined. The phylogenetic relationships between S-alleles in the germplasm studied were determined by the homology between their sequences and dendrograms were obtained for each primer pair. The Maximum Likelihood (homology) ranged from 84 to 100%. Most sequences were similar to cultivated almond (Prunus dulcis) or to the European wild almond (P. webbii). Twenty-six alleles for the first and the second introns were registered in the database in the GenBank. Two sequences of the first and second introns, which were taken from Prunusnairica and had similarity in GenBank, were registered in the database under a common sequence of the first and second intron. Analysis of phylogenetic relationships (dendrograms) among S-alleles from wild almond species as well as S-alleles cluster relations showed most pairs of alleles well supported by bootstrap.