لخّصلي

Wheat, being a staple food for many, faces a major challenge in the form of salinity stress, which hinders its production globally. This study focused on the genetic improvement of wheat for salinity tolerance using mutations. Seven wheat accessions, including the original variety Sakha 8 and six M5 derived mutants, were evaluated for their salinity tolerance.

Mutants 1, 2, 3, and 5 exhibited remarkable tolerance, while other genotypes showed good tolerance as well. These promising genotypes demonstrated high genetic stability, displaying desirable agro-morphological and physiological traits related to salinity tolerance. The genetic advance values, although low, indicated the success of mutation breeding in achieving relative salinity tolerance.

Molecular marker analysis using ISSR primers revealed significant genetic diversity among the six mutants and the original variety. The high degree of polymorphism (93.06%) confirmed the distinct genetic profiles of the mutants. Overall, the study highlighted the potential of mutation breeding for developing wheat genotypes with enhanced salinity tolerance.

Abstract
Background: Given the strategic importance of wheat being the staple food for the vast majority of people, it was necessary to know reasons for the contraction and decline of its area globally and consequently its lower yield. Among the most important of these problems is the problem of a high level of salinity in both soil and irrigation water coming at the forefront of environmental challenges that hinder its production process at the local and global levels. Therefore, the genetic improvement of wheat for salinity tolerance was one of the most important priorities of this investigation.
Results: The seven wheat accessions (Sakha 8 and its six M5 derived mutants) succeeded in drawing unique cases of salinity tolerance and were excellent especially mutants 1, 2, 3, and 5. The rest genotypes were coming in the second rank for this purpose and were very good in this regard. The promising wheat genotypes which recorded high salinity tolerance in the recent investigation exhibited also high genetic stability. This fact was proved after estimating some agro-morphological and physiological traits related to salinity tolerance based on evaluating some important genetic parameters besides salinity tolerance indices under stress experiment compared to the control treatment within two seasons. Data evaluated of expected genetic advance (GA) based on 5% selection proved that all values calculated during the two seasons under both treatments appeared low for all studied traits in this regard. However, it reflects the success of breeding for salinity tolerance in wheat using mutations but in relative terms. Molecular marker analysis profile using the six ISSR primers exhibited a total of 173 markers, 12 of them were monomorphic, while that 161 bands appeared polymorphic included 56 unique bands or positive markers and 7 negative markers with 93.06 % (polymorphism).
Conclusion: The original wheat variety (Sakha 8) and its six M5 derived mutants exhibited high tolerance of salinity stress in all studied traits based on all genetic parameters and salinity tolerance indices calculated for both seasons under salinity treatment compared to the normal conditions. DNA fingerprinting analysis as well for the six wheat mutants besides the local variety proved that these genotypes were recorded highly genetic differences among them.