EFFECTS OF SALICYLIC ACID APPLICATION ON COLD TOLERANCE AND GENE EXPRESSION IN PEPPER (Capsicum annuum L.) SEEDLING.

Abstract

This project was developed to investigate the contribution of salicylic acid to development of pepper seedlings grown in low temperature (0 0C) conditions. The research was carried out in the controlled plant growing cabinet in the research- investigation area of the Department of Horticulture, Faculty of Agriculture, Siirt University. As a vegetable material, Urartu F1 pepper type (capia) which is used in greenhouse cultivation has been used. As a dose of different salicylic acid; 0.01 and 0.05 mmol doses were used. The dose of 0 mmol salicylic acid was used as control group. Application frequency; It was applied 1 time, 2 times and 3 times. 3 different cold application times were also investigated; 24 hours, 48 hours and 72 hours. The experiment was designed in randomized plots and 3 replications. In the pepper seedlings, the effect on the weight loss of the seedlings, the rate of loss in the seedlings, the turgority of the seedlings, the rate of living seedlings, the signs of cold damage and the rate of continuing the development of seedlings and the effect of the seedlings on the WRKY genes were investigated. At the end of the research; there was no statistical difference between the results of Turgorite and Cold Loss in seedlings. The 0.01 mmol dose of salicylic acid showed a positive effect on the rate of seedlings while the 0.05 mmol dose showed the most positive effect on turgorite protection. The control group, which did not use salicylic acid, had the most positive result after the application of cold in the seedlings. Between holding times at low temperatures, the 24-hour hold is recorded as the best time for all measurements except wilt. It has been determined that the frequency application performed 3 times is better than the other (1 time and 2 times) applications. Considering the administration of both salicylic acids, it was found that 0.05 mmol dose had a clearer and more understanding response to the expression of WRKY gene.