A hydroponic experiment was conducted to assess whether grafting with Cucurbita rootstocks could improve the salt tolerance of melon scions and to determine the physiological, biochemical, and nutritional responses induced by the rootstocks under salt stress. Two melon (Cucumis melo L.) cultivars (Citirex and Altinbas) were grafted onto two commercial Cucurbita rootstocks (Kardosa and Nun9075). Plants were grown in aerated nutrient solution under deep water culture (DWC) at two electrical conductivity (EC) levels (control at 1.5 dS m⁻¹ and salt at 8.0 dS m⁻¹). Hydroponic salt stress led to a significant reduction in shoot and root growths, leaf area, photosynthetic activity, and leaf chlorophyll and carotenoid contents of both grafted and nongrafted melons. Susceptible plants responded to salt stress by increasing leaf proline and malondialdehyde (MDA), ion leakage, and leaf Na⁺ and Cl⁻ contents. Statistically significant negative correlations existed between shoot dry biomass production and leaf proline (r = −0.89), leaf MDA (r = −0.85), leaf Na⁺ (r = −0.90), and leaf (r = 0.63) and root (r = −0.90) ion leakages under salt stress. Nongrafted Citirex tended to be more sensitive to salt stress than Altinbas. The Cucurbita rootstocks (Nun9075 and Kardosa) significantly improved growth and biomass production of grafted melons (scions) by inducing physiological (high leaf area and photosynthesis), biochemical (low leaf proline and MDA), and nutritional (low leaf Na⁺ and ion leakage and high K⁺ and Ca⁺⁺ contents) responses under salt stress. The highest growth performance was exhibited by the Citirex/Nun9075 and Citirex/Kardosa graft combinations. Both Cucurbita cultivars have high rootstock potential for melon, and their significant contributions to salt tolerance were closely associated with inducing physiological and biochemical responses of scions. These traits could be useful for the selection and breeding of salt-tolerant rootstocks for sustainable agriculture in the future.

The positive response of grafting by tolerant rootstocks or scion-stock interactions on yield and fruit traits of tomatoes under saline conditions is attributed to several physiological and biochemical changes. In this study, we investigated some tolerance mechanisms by which grafting on wild rootstocks in tomatoes can prevent or minimize the effects of salt stress in plants under hydroponics conditions. Two tomato cultivars H2274 and Galaxy were grafted onto three S. pimpinellifolium, three S. habrochaites, S. lycopersicum L. × S. pimpinellifolium and S. lycopersicum L. × S. Habrochaites hybrid tomato genotypes. Plants were grown in hydroponic culture at two electrical conductivity (EC) levels (control at 1.5 dSm^-1 and salt at 8.0 dSm^-1). Salt stress led to a significant reduction in biomass growths of both grafted and nongrafted tomatoes. However, the plants that are least affected by salt stress are those grafted on wild tomato rootstocks. Leaf nutrient contents were significantly affected by rootstocks under both control and salt stress conditions. In this study, under saline conditions, plants grafted on wild rootstocks had higher N, P, K, Ca, Mg, S, Mn, Fe, Zn and B contents in leaf tissues and lower Na and Cl contents than ungrafted plants. Biochemical and physiological results revealed that S. pimpinellifolium and S. habrochaites have inherited salt tolerance from their genetic background. These wild tomato genotypes can be used as rootstocks in tomato breeding programs to develop salt-tolerant tomatoes or in grafting techniques under saline irrigation conditions.

This study was conducted to determine the response of Salvia tomentosa Mill. and Salvia officinalis L. to different salinity levels. The salvia plants were grown in 8 L pots filled with the continuously aerated nutrient solution under different salt levels 1 (control), 2, 3, 4, 5 and 6 dS m-1 in fully automated climate chambers. The fresh and dry weight of shoot and root, stem length, leaf area, SPAD, CO2 fixation, root length, root diameter, root volume, leaf Na+, K+, Ca++ Cl- content, and amount of essential oil were determined. The increasing salt level decreased significantly plant growth of both Salvia species. However, highly significant differences were found between two Salvia species in terms of shoot and root biomass. Generally, S. tomentosa showed better plant growth performance in plant growth compared to S. officinalis. The Na+ and Cl- content of the leaves significantly increased with increasing salt concentration and the increase was higher in S. tomentosa. The amount of K+ in the leaves decreased due to the increasing salt concentration, while the amount of Ca++ varied depending on the dose. The study showed that the essential oil contents of the sage leaves could be increased with the moderate salt application. The increase in essential oil due to salt stress was higher in S. officinalis. The results showed that Salvia species can be cultivated in low and medium saline soils, second class waters can be used for irrigation of sages and essential oil yield of sages can be increased by using salt stress.