Role of Spermidine and γ-Aminobutyric Acid and Hydro priming on alleviation of salinity effect in germination and growth parameters of cucumber (Cucumis sativus L. cv. Beit Alpha) seed

In order to investigate Spermidine and γ-Aminobutyric Acid (Gaba) role on germination features and growth parameters of cucumber under salinity stress, an experiment was conducted as factorial layout based on the completely randomized design at university of Torbat Heydarieh, Iran in 2108 . The first factor consists of seed priming with Gaba (5 and 10 mM), Spermidine (5 and 10 mM), the combination of them and hydropriming in distilled water, and no treatment. The second factor was three salinity levels (0, 1.8, 9.5 dS/m). Results showed that seed priming with Gaba and Spermidine positively affected the shoot and seedling fresh weight, root length, and root dry weight. The highest value of germination percent, relative germination, and germination index was seen in no salinity and 5 mM Spermidine and 10 mm Gaba application (by 19 percent more than control). Using hydropriming, Spermidine and Gaba significantly improved cucumber seedling growth under 9.5 dS/m salinity in comparison to zero salinity treatment. Salinity caused a reduction of germination percent from 84 to 17 %, but employing seed priming treatments caused an enhancement of relative germination in salinity condition. In other words employment of hydropriming and these amendments induced in the alleviation of salinity stress. In attention to application of hydropriming as an inexpensive and convenient method in comparison to other treatments it could be recommended.