Cold tolerance evaluation in some bread wheat genotypes in seedling stage under laboratory conditions

Sever coldness causes damage to the wheat and affect its growth and yield. Therefore, this experiment was conducted in controlled conditions to investigate freezing tolerance of eight wheat genotypes. Combination of temperature (+3, -3, -5, -7 and -9 °C) and genotypes (Bahar, Parsi, Pishtaz, Pishgam, Chamran, Zarin, Sivand and Marvdasht) as a factorial based on completely randomized design with three replications. Survival percentage, dry weight, number of leaves per seedling and seedling height were measured two weeks after freezing in the glasshouse. The results showed that with decreasing seedling survival due to temperature drop, dry weight, height and number of leaves in seedlings also decreased. The genotype of Marvdasht had the highest freezing resistance (-5.2 °C) was superior to other wheat genotypes in terms of dry weight, seedling height and number of leaves per seedling. Parsi and Zarin genotypes were in the next rank. While the Pishtaz genotype was a highly sensitive genotype to freezing. According to the results of this research, it can be recommended that in the regions with the probability of frostbite, it is better to avoid cultivating the Pishtaz genotype and instead use Marvdasht, Parsi and Zarin genotypes.