The effect of light emitting diodes (LED) on quality characteristics of grape varieties in vitro conditions

Light is one of the most important environmental variables affecting plant growth and morphology. The use of artificial lighting not only increases productivity and quality, but also becomes more important in agriculture because it enables agriculture, especially in closed areas where natural light is insufficient. Light-emitting diodes (LEDs), a type of artificial lighting, are also widely used in scientific research and crop production because they can be tuned to a narrow and specific spectral composition, are long-lasting, durable and small, and remain relatively cool. In this study, the effects of light quality (daylight, red and blue light) on plant growth, photosynthetic activity and antioxidant enzyme activity in Michele Palieri and Italia grape varieties under in vitro conditions were investigated. Compared to daylight, blue LED application supported shoot elongation, fresh weight and chlorophyll a/b ratio, and caused a decrease in photosynthetic parameters. Blue LED application increased the SPAD value and also obtained the highest data in ion flow measurements. Cultivars showed variable responses to antioxidant enzyme reactions. In Michele Palieri variety, red LED was more effective in increasing the amount of protein, daylight and blue LED were more effective in increasing the amount of SOD enzyme, and daylight was more effective in increasing the amount of APX enzyme. In the Italia variety, blue LED was more effective in increasing the amount of protein, daylight was more effective in increasing the amount of SOD enzyme, and red LED was more effective in increasing the amount of APX enzyme. Chlorophyll a, chlorophyll b and total chlorophyll values were measured under the highest daylight conditions. As a result, it was concluded that LED light applications of different qualities have different effects on yield and quality among grape varieties and that research on this subject should be increased. Key Words: Italia, Michele Palieri, LED, Antioxidant Enzyme Activity, Chlorophyll, APX, Ion Flux, Caroten.