Effect of different rootstocks on yield, quality and biochemical content of tomatoe under salt stress and alkaline conditions

The aim of this study is to determine the effect of grafting on different rootstocks on tomato yield, quality characteristics and iochemical content under salt and alkaline stress. 9 different tomato graft rootstocks were used in the experiment (Amaron F₁ (Antalya Tarım), Beaufort F₁ (Antalya Tarım, onsanto), Hamarat F₁ 9T7379 (Multi Seeds), Embajador RZ Fı (Rijk zwaan), Armstrong F₁ 500292 (Syngenta), UG 5433 Fı, Suketto F₁ (United Genetics), Sarar F₁ and Kalyon Fı (Yüksel Tohum)). Ungrafted and self-grafted plants were used as controls. Alsancak F₁ pole tomato variety (Yüksel Tohum) was used as a commercial variety in grafting. The seedlings were planted on April 20, 2023. Plants were grown in the greenhouse under soilless farming conditions and in peat + perlite (2:1) environment. Modified Hoagland nutrient solution was used to fertilize the plants. Control and 3 different salt concentrations and control and pH 8.1 doses were used in the experiment. In the control application, Hoagland nutrient solution was used with an EC of 1.80 dS m‾¹ until flowering and an EC of 2.0 dS m‾¹ after flowering. The pH of the nutrient solution was adjusted to 6.5. In the salt stress application, 25, 50 and 75 mM NaCl were used. In alkaline stress application, the pH of irrigation water was adjusted to 8.1 using sodium bicarbonate. The experiment was carried out with 3 replications according to the randomized plot design, and 6 plants were grown in each plot. In the study, marketable yield, number of marketable fruits, average number of fruits, number of discarded fruits, discarded yield, water soluble dry matter, fruit-leaf dry weight, electrical conductivity, pH, titratable acid amount, fruit vitamin C content and fruit flesh hardness were measured. . Leaf chlorophyll value (SPAD), macro and micro nutrient element contents (( P, K+, Na+, Ca2+, Mg2+, Fe2+, Mn2+, Cu2+, Zn2+ ve B3-), SOD, CAT, APX, MDA, GR, proline content, H₂O₂ level and POX activities were examined. While salt and alkaline stress applications caused significant decreases in marketable yield, number of marketable fruits, total yield and average number of fruits, losses became higher as the salt concentration increased. Plant development and yield parameters of grafted plants were found to be significantly higher than ungrafted and self-grafted plants under both salt stress and alkaline conditions. The effects of grafted plants under stress conditions differed depending on the rootstocks. While salt stress provided significant increases in the quality parameters affecting taste and aroma in tomato fruits, the effects of grafting applications varied according to the rootstocks. Increasing salt concentrations provided a linear increase in leaf chlorophyll value, water soluble solids, titratable acidity, vitamin C, electrical conductivity and fruit flesh hardness. No significant relationship was found between fruit pH content and alkaline-salinity stress. Apart from the control plants, among the 9 rootstocks, no rootstock stood out clearly under salt and alkaline stress conditions. However, some vaccine combinations provided an increase in quality parameters compared to the control. Especially at high salt concentrations, grafting increased the water-soluble solids, titratable acid content and fruit flesh hardness. Although increases were observed in SOD, CAT, APX, MDA, GR, proline content, H2O2 level and POX activities due to salt stress and pH increase, better results were obtained in some vaccine combinations compared to the control.