Molecular studies for drought tolerance in some Egyptian wheat genotypes under different irrigation systems

Abstract

Abstract This research work was carried out to evaluate drought stress for the differentiation of bread wheat (Triticum aestivum L.) genotypes in their ability to tolerate drought. An experiment was carried out on six genotypes (‘Sides 1’, ‘Shindwell 1’, ‘Gemmiza 9’, ‘Sakha 93’, ‘Saheel 1’ and ‘Masr 2’). A randomized complete block design with three replications along two separate tests under the drip and the sprinkler irrigation systems was used in this experiment. One of the irrigation treatments applied the normal amount of irrigation water and the other applied end-season drought stress conditions through two successful agricultural seasons 2016/2017 and 2017/2018. The impact on biomass, grain yield and water productivity of the six genotypes was measured. Random amplified polymorphic DNA (RAPD) markers were used to evaluate genetic variation among the six genotypes. PCR–RAPD analysis showed that there were several differences in both the size and number of bands between the varieties. Based on these markers, genetic similarity coefficients were calculated and a dendrogram was constructed. The dendrogram analysis delineated three major clusters. The current study showed that RAPD markers are useful in the assessment of the genetic diversity among the wheat genotypes. The drip irrigation system gave the highest values of both the biomass and the grain yield for the six genotypes, while the sprinkler irrigation gave the lowest values. Comparing the six genotypes in terms of the biomass, grain yield and water productivity, it was concluded that, the highest water productivity (WP) genotype was Sides 1, except during water stress with the sprinkler irrigation system. It was followed by genotype Sakha 93, then genotype Shindwell 1, while genotype Gemmiza 9 gave the lowest in all cases, except without water stress under drip irrigation.