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Grape softwood cuttings of Khoshnaw cultivar were cultured using tissue-culture methods to study the effect of iron nanoparticles and potassium silicate under salinity conditions during the 2015-2016 growing season. The treatments consisted of salinity stress (0, 50, and 100 mM NaCl), nanoparticles of iron (0, 0.08, and 0.8 ppm), and potassium silicate (0, 1, 2 mM). The results also showed that the application of iron nanoparticles and potassium silicate significantly increased the total protein content and reduced proline, enzymatic antioxidant activity and hydrogen peroxide. Salinity stress reduced membrane stability index while increased malondialdehyde content. Increase of membrane stability index and reduction of malondialdehyde content were obtained for 2 mM potassium silicate and 0.8 ppm iron nanoparticle. Iron and potassium silicate were shown to lower the sodium content and increase the potassium content under salinity-stress conditions. The highest ratio of sodium to potassium was observed in plants under salinity conditions (100 mM) treated with neither iron nanoparticles nor potassium silicate; conversely, the lowest ratio was achieved in plants treated with both 0.8 ppm iron nanoparticles with 1 mM and 2 mM potassium silicate under non-stress conditions. These results indicate that the application of micronutrients in stressful conditions is a suitable method to compensate for the negative effects of salinity stress. Tissue culture in this study was shown to be an economically efficient and applicable technique for producing grape softwood cuttings to be used in experiments.

In order to evaluate the effect of different levels of drought stress on some physiological parameters in strawberry, one experiment with potted strawberry cultivars 'Kurdistan' and 'Selva' was conducted in summer 2008. The experiment was performed with four drought stress treatments [control (75% of field capacity), S1: mild drought stress (50% of field capacity), S2: severe drought stress (25% of field capacity) and R: one day after rewatering]. Physiological parameters such as: leaf relative water content (RWC), membrane stability index (MSI), net CO2 assimilation rate (A), stomatal conductance (gs), transpiration (E), water use efficiency (A/gs), chlorophyll, proline and soluble carbohydrate contents were measured in leaves of strawberry subjected to different drought stress conditions as well as one day after rewatering. The results showed that RWC, MSI, A, gs, E, and chlorophyll of two cultivars decreased as soil water content was reduced. A/gs was highest under mild water stress for both cultivars. 'Kurdistan' had lower A, gs and E than 'Selva'. RWC, MSI and A/gs of 'Kurdistan' were higher than 'Selva'. Recovery of these parameters was faster for 'Kurdistan' than 'Selva'. Chlorophyll contents of 'Kurdistan' was higher than 'Selva'. Chlorophyll recovery didn't occur one day after rewatering. Amount of proline and soluble carbohydrates increased under severe drought stress. 'Kurdistan' had higher proline content compared to 'Selva' under severe drought stress. Amount of proline and soluble carbohydrates were reduced in both the cultivars one day after rewatering. This study revealed that moderate drought stress affects gas exchange while severe drought stress affects chlorophyll, proline and soluble carbohydrates levels.

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In the present study, multiplication efficiency of Alstroemeria ligtu hybrid was investigated. Bases of the first seedling leaves grown in vitro were used as initial explants. The explants were cultured in the MS media containing 3% sucrose, 0.7% agar at pH 5.8, five N6-benzylaminopurine (BAP) concentrations (0, 0.5, 1, 1.5 and 2 mg·1-1) and three indole-3-butyric acid (IBA) concentrations (0, 0.1 and 0.2 mg·1-1). The cultures were incubated at 21 ± 2 °C under photoperiod 16/8. After three subculturings (3 weeks-long each) the number of rhizome, shoots, buds, leaves, and roots, length of shoots and roots were recorded. Adventitious shoots formed directly on the leaf bases without callus intervention. Their number was affected by BAP concentrations. The highest shoots number, six per explants, was obtained at 1 mg·1-1 BAP and 0.1 mg·1-1 IBA. The shoot length decreased with the increasing concentration of BAP. The highest root number (2.7) was formed on shoots cultured on the MS medium containing 0.5 mg·1-1 α- naphthalene acetic acid, and the highest rhizome number (2.2) was formed on the medium with 0.5 mg·1-1 BAP. In vitro rooted plantlets were able to survive and acclimatize in the greenhouse.