The effects of UV-B irradiation on development and quality of tomato, cucumber and eggplant seedlings

The aim of the study was to investigate the effects of UV-B irradiation on development and quality of tomato, cucumber and eggplant seedlings. Tomato (Solanum lycopersicum L. cv. Alsancak-RN), cucumber (Cucumis sativus L. cv) and eggplant (Solanum melongena L. cv.) seedlings were subjected to UV-B irradiation 0 kJ/m2/day, 10.8 kJ/m2/day and 16.2 kJ/m2/day for 10 days (76.5 min/day-114.75 min/day) when they reached to the first true leaves stage. After the treatment, seedling lengtht, number of leaves, leaf area, root diameter, root length, root dry matter content, dry matter content of plant above soil surface, H2O2 content, macro-micro elements were determined as well as measuring chlorophyll content of leaves and leaf colour. The content of chlorophyll in the tomato seedling was increased by UV-B irradiation at 10.8 kJ/m2 /day and in the root and upper plant part magnesium content decreased at 16.2 kJ/ m2/day UV-B irradiation. Root diameter increased with dose of UV-B irradiation. In the 16.2 kJ/m2/day UV-B irradiation, while the content of iron in the root dry matter and the upper plant part increased, H2O2 and the content of calcium in the upper plant part decreased in the 10.8 kJ/m2/day UV-B irradiation. It was determined that the manganese and zinc content of tomato seedlings decreased with UV-B irradiations and phosphor content increased with UV-B irradiation of 10.8 kJ/m2/day. The content of chlorophyll in cucumber seedling increased by 10.8 kJ/m2/day UV-B irradiation. while leaf number and leaf area increased in UV-B irradiation of 10.8 kJ/m2/day, they decreased with UV-B irradiation of 16.2 kJ/m2/day. Decrease was observed on the root diameter, root length, upper plant part dry matter and manganese with UV-B irradiations. The nitrogen, protein, calcium; root calcium, iron, zinc and H2O2 contents of upper plant part increased with UV-B applications. Whereas the magnesium and potassium contents of the upper part plat decreased at 16.2 kJ/m2/day UV-B irradiation, the phosphor content at the upper plant part increased with 10.8 kJ/m2/day UV-B irradiation. Chloroma value and phosphor content of the upper plant part in the eggplant seedlings decreased in 10.8 kJ/m2/day UV-B irradiation. L* color value, root collar diameter, leaf area, upper plant part magnesium and potassium content in seedlings decreased in UV-B irradiation. It was determined that the content of nitrogen and protein in the upper plant part increased with the application of 10.8 kJ/m2/day. The content of zinc in the root and upper plant part was increased by UV-B irradiation of 10.8 kJ/m2/day and decreased by 16.2 kJ/m2/day of UV-B irradiation. UV-B irradiation caused morphological and physiological changes on the seedling depending on the dose and plant species.