Identification of Self-Incompatibility Alleles in some Iranian Native Pear Cultivar

Bearing of pear trees is affected by various genetical and environmental factors. Pear cultivars are gametophytic self-incompatible that is under control of multi allelic S locus and therefore need to compatible pollinizer cultivars for economical bearing. This research was conducted in order to identify S-alleles of several indigenous pear cultivars including Dargazi, Konjuni, Beyrouti, Ghosi and Amroud-II by PCR techniques. Genomic DNA of plant materials quantitatively and qualitatively were evaluated after extraction. Subsequently, S-alleles were partially amplified by using specific Sall-F/Sall-R1 primers, as well as FB-F/FB-R1 and FB-F/FB-R2 primer pairs designed via alignment of all Pyrus S-alleles. Last primer pairs designed as semi nested for former pair. For pecise identification of S-alleles, amplified regions were restriction digested by selected DraI, EcoRI, MspI and HaeIII enzymes. The primers could amplify all S-alleles in all cultivars and totally 5 alleles including S1(Sj, Se) in Beyrouti, Ghosi and Amroud-II, S2(Sl) in Dargazi, S4(Sb) in Beyrouti and Dargazi, S5(Sa) in Konjouni, S13(St) in Ghosi and S42 in Konjouni were identified. The results demonstrating presence of rare S42 allele from Ussuri pear (Pyrus ussuriensis Maxim.) from Manchuria in China in Konjouni cultivar that is the first report of gene flux of this species in indigenous cultivars.