The effect of gamma rays irradiation on the growth and flavonoid content of kenikir (Cosmos caudatus Kunth.)

Abstract

The aim of the research was to identify agronomical characteristics and flavonoid content of kenikir (Cosmos caudatusKunth.) irradiated by gamma rays with several dosages. Seeds of kenikir were irradiated by gamma rays in radiator chamber 4000 A using 60 Co source at Isotope and Radiation Application Center, BATAN, Jakarta. Dosages of irradiation ranging from 50 Gy-300 Gy with interval 50 Gy. Subsequently, irradiated seed along with unirradiated seeds (control) were planted in Greenhouse Agriculltural Faculty, Universitas Sumatera Utara (± 32 meters above sea level). The variation of agronomical characters (plant height, leaf number, stem diameter, number of branches per plant and flowering age) were observedfrom 1 st week up to 9 th week after planting. Data were analyzed by t-test using minitab 18 program. The flavonoid content of leaves extract were analyzed using spektrofotometer UV-VIS in Research Laboratory, Faculty of Pharmacy, Universitas Sumatra Utara. The results showed that the mean values of M1 generation of all agronomical characters observed were lower than control plants whereas the highest flavonoid content was found in the population of gamma ray irradiated at 100 Gy.