Induksi Mutasi Kromosom Dengan Iradiasi Sinar Gamma Cobalt 60 Untuk Merakit Padi (Oryza sativa) Tahan Kekeringan Secara In Vitro

A lot of people in the world choose rice as their main source of carbohydrate beside maize and wheat. The increasing of world population make increasing of the rice  demand. Increasing of the rice demand doesn’t followed by the rice supply.  In order to solve that problem, researcher try to find a new paddy cultivar which is can be planted in dry area. This research aims to study the osmotic pressure that still can be accepted by paddy var. Sintanur,  to study LD50 (lethal dose 50) value in the paddy especially in Sintanur and to study the interaction between irradiation and the osmotic pressure. In this research, paddy var. Sintanur is irradiated by gamma ray of Cobalt60 at six dosages 0 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 500 Gy. Then each irradiated seed is planted at four kind of mediums that contains Polyethylene glycol (PEG) at four levels of concentration are I0 (0 g/l PEG), I1 (116,538 g/l PEG), I2 (174,6 g/l PEG) and I3 (219,547 g/l PEG). Based on the data analyzed, the highest PEG concentration for drought tolerant selection in paddy var. Sintanur is 174,674 g/l PEG. There is an interaction between irradiation and PEG medium that influencing plant height and shoot multiplication. LD 50 (lethal dose 50) of paddy var. Sintanur is 375 Gy.   Keyword: paddy, Sintanur, cobalt60, drought tolerant, irradiation