Validation of SSR Molecular Markers Linked to Drought Tolerant in Some Wheat Cultivars

Abstract

The present study was carried out to conduct drought tolerance in three wheat cultivars including susceptible (Gemmiza7) and tolerant (Sakha93 and Sahel1). Molecular characterization was done by 26 SSR markers located on chromosome7 which was associated with drought tolerance in many previous studies. 26 SSR markers were polymorphic and thus showed 100% polymorphism. The number of alleles per locus varied from 2 to 3 alleles with an average (2.62). The polymorphism information content (PIC) value ranged from 0.34 to 0.59, with a mean of 0.51. The discrimination power (Dp) value ranged between 0.67 and 0.78 with an average of 0.71 per locus and Heterozygosity (He) value varied from 0.44 to 0.67 with an average of 0.59. The genetic relationships estimated by the polymorphism of SSR markers revealed a greater level of genetic variability in wheat cultivars of wide adaptability and applicability. Whereas an average of combined probability value for the SSR markers was 6.15 x 10-16, suggests the capability of the marker system to distinguish identity and purity of wheat cultivars. In addition to the SSR markers revealed various bands that were either absent or present within tolerant cultivars (Sakha93 and Sahel1) which were altogether absent in susceptible cultivar (Gemmiza7). Also, SSRs of diagnostic and curatorial importance were discerned as ‘stand-alone’ molecular descriptors for barcoding the application of DNA sequences of standardized genetic markers for the identification of wheat cultivars. However, the genetic information in this study could provide useful information to address breeding programs and germplasm resource management.