Molecular Characterization of Some Syrian Pears ( Pyrus Syriaca Boiss ) Genotypes Using SSR Marker = التوصيف الجزيئي لبعض طرز الأجاص السورية Pyrus Syriaca Boiss باستخدام تقنية ال SSR

Abstract

The present investigation was carried out to study the genetic variability and the relationship among six Syrian pears; 3 wild type genotypes (W.T 1 , W.T 2 , and W.T 3) of pyrus syriaca Boiss, 3 Syrian pyrus cultivars (Meskawi, Romi and Abu-satel), and Liconte cultivar by using fifteen SSR primer-pairs. Fourteen primer pairs of them were able to characterize the studied pear genotypes, they revealed 47 alleles, of which 44 were polymorphic (93.6%) among all genotypes, when focusing on the Syrian pear genotypes only 42 of 45 alleles were polymorphic (93.3%). The number of alleles per primer-pairs ranged from 1 to 6 alleles with an average 3.4. Liconte revealed low genetic relationship with Syrian pear genotypes which indicate that the two groups belong to different species or subspecies. On the other hand, Meskawi cultivar revealed the highest genetic similarity with W.T 3 (65%). The dendrogram clustered the seven pear genotypes into two clusters where Liconte and Romi genotypes grouped in the first cluster, and the other genotypes grouped in the second cluster. A total of 12 SSR primer-pairs out of 14 characterized the seven pear genotypes by 20 unique SSR alleles (17 positive and 3 negative). The average of expected heterozygosity (H e) was 0.263 and the marker index was 11.57. Consequently, the obtained data reflected the ability of SSR marker to identify the genetic variability among the seven pear genotypes.