مشخصات پژوهش

During the course of cold acclimation, a key process associated with plant cold tolerance, some biochemical components may be up- or down-regulated. In carrying out this experiment, the objective was to investigate the correlation between acclimation and hydrogen peroxide (H2O2) and malondialdehyde (MDA) production under monitored conditions (regular chamber and cold regime) in 20 barely genotypes through in a split plot experiment, with temperatures as main plot and genotypes as a sub plot, based on a complete randomized blocks design with three replicates. According to the results, there was a significant difference in the amount of H2O2 and MDA between the two temperature conditions, so was the difference between genotypes regarding MDA content. However, no significant difference was observed between genotypes concerning H2O2 content. Further analysis of variance, for MDA content before and after acclimation as well as discrepancies between the two conditions, was conducted using a complete randomized block design, which robustly discriminated the genotypes performance after cold acclimation, and revealed the significant difference between the two temperature conditions. Some genotypes (EC83-12 and Schulyer) possessed the least amount of H2O2 and MDA, hence designated as tolerant, and genotypes (Kavir and Aths) with highest amount of H2O2 and MDA were considered cold sensitive. There also existed a positive, significant correlation between MDA and H2O2 contents in the event of difference between control and post- acclimation treatment. Finally, cluster analysis of the mean contents of MDA and H2O2 in genotypes, using “linkage between groups” method, resulted in four groups as sensitive, semi-sensitive, semitolerant and tolerant. Present study has been planned to examine the role of MDA and H2O2 related to cold stress of tolerant and sensitive barley.