Effects of Different Spermidine Concentrations on Germination of Three Cucumber Cultivars under Low Temperature

The effect of spermidine on seed germination of three different cucumber cultivars under cold stress was studied as a 4×2 factorial experiment by using a completely randomized design with 4 replications. First factor was 4 concentrations of spermidine consisted of 0 (control)، 0. 1، 0. 5 and 1 mM and the second one was three cucumber cultivars consisted of ‘Emperator’، ‘Amiran’ and ‘Rashid’. For this purpose، 50 seeds of each cultivars were placed on filter papers inside steriled petry dishes and spermidine solutions were added to them according to each treatment. All petry dishes were placed in a 13°C temperature of the incubator until end of the experiment and germinated seeds were counted daily. The measured traits were percentage of germination، plumule length، radicle length، dry and fresh weight of the plumule and radicle. The results showed that treating seeds of ‘Rashid’ cultivar with 0. 1 mM spermidine increased percentage of germination، plumule and radicle length، fresh and dry weights of radical compared with control. Treating ‘Rashid’ seeds with high concentration (1 mM) of spermidine showed inhibitory effects on all measured characteristics، but in ‘Amiran’ cultivar only decreased percentage of germination، plumule and radicle length، fresh and dry weight of ridicle.