MORPHOLOGICAL CHANGES OF PEPPER VARIETIES (CAPSICUM ANNUUM L.) RESULTED FROM UV-C LIGHTS AND GAMMA-RAY RADIATION SOURCES

Mutation breeding is a method frequently used in plant breeding programs to develop highyielding varieties that are resistant to biotic and abiotic environmental factors and to determine genetic diversity.This study aimed to determine the effects of different doses of ultraviolet light and gamma rays on the morphological characteristics of some pepper varieties (ermik (local variety), Kandil and burun).The experiment was realized in Dicle University, Faculty of Agriculture, Department of Horticulture laboratory and polycarbonate greenhouse.In the paper, the effects of different gamma ray doses (0, 50, 100, 200, 300, 400 and 500 Gy) and ultraviolet light sources kept on 0.5 and 1.0-m distances under priming and non-priming conditions for one and 2 h were assessed on root and shoot development, leaf color and proline values of pepper seedlings.A notable reduction realized in root collar diameter, root length, plant fresh weight, root fresh weight, root dry weight, plant dry weight, color values (l, a, b) and proline content of pepper varieties with increasing doses of gamma ray radiation.The ultraviolet light sources kept on 0.5 and 1.0 m significantly resulted in changes in all features.Consequently, ultraviolet light sources were more effective for genetic diversity than gamma rays.Finally, 200-300 Gy dosses and ultraviolet light kept on 0.5 m were more efficient than other treatments.In the future, it will be effective to investigate the effects of these treatments and their combinations to obtain mutants with desired characters.