Genetic Diversity in Wheat Genotypes Using Simple Sequence Repeat (Ssr) Markers

Abstract

A total of 73 genotypes including 65 hexaploid (Triticum aestivum L.) and 8 tetraploid (Triticum durum L) wheat varieties were used in this study. Eleven microsatellite markers were used to test the genetic diversity of wheat genotypes, yielding a polymorphism. The total number of detected alleles was 89 with an average allele number of 8.1 per locus. The maximum number of polymorphic alleles (9 bands) was obtained by the primer SSR-9 while the minimum number (1 allele) was recorded for primer SSR-11 with an average 5 alleles per primer. Polymorphism percentage ranged from as low as 50 % (SSR-1, SSR-2 and SSR-5) to as high as 100% (SSR-10 and SSR-11) with an average of 68.24 %. Eleven alleles at molecular size [219 bp and 188 bp (SSR-1), 239 bp (SSR-3), 635 bp and 503 bp (SSR-4), 358 bp and 331 bp (SSR-8), 250 bp, 226 bp and 210 bp (SSR-9) and 532 bp (SSR-11)], were present only in bread wheat genotypes, while one allele at molecular size 312 bp generated with primer (SSR-6) was unique to durum wheat genotypes. These alleles could be used as marker to distinguish the durum wheat from the bread wheat genotypes. Polymorphism information content (PIC) value ranged from 0.06 (primer SSR-6) to 0.2 (primer SSR-11) with an average value of 0.13. These results reflect the wide range between the frequencies of alleles at loci of SSR studied in the tested wheat varieties. The dendrogram grouped the 73 wheat genotypes according to their ploidy levels into two main clusters. Cluster 1 included the durum wheat genotypes, while cluster 2 contained all bread wheat genotypes.