In vitro selection of callus from local Badui rice plant (Oryza sativa l.) on polyethylene glycol (PEG 6000) medium to obtain drought-resistant variants

Rice (Oryza sativa L.) is a major food crop commodity and a primary source of carbohydrates. Prolonged drought in Indonesia leads to a decline in rice productivity and increases the risk of crop failure. Therefore, the development of rice varieties resistant to drought stress is essential to support food security. This study aims to determine the most optimal medium for callus induction of local Badui rice and to measure the resistance level of the selected callus under PEG 6000 treatment. The research procedures included callus induction, drought stress selection using PEG at different concentrations, observation, and data analysis. The results showed that N6 medium without growth regulators and N6 medium with NAA 1.5 ppm failed to produce callus. The addition of 2,4-D at 1 ppm, 2.5 ppm, and 5 ppm generated yellowish-white friable callus, whereas the combination of NAA 1.5 ppm and BAP 0.25 ppm produced black compact callus. The addition of 2,4-D 1 ppm resulted in the highest percentage of callus formation, callus weight, and callus diameter, making it the optimal medium for callus induction. Increasing concentrations if PEG 6000 caused callus colour changes, reduced callus weight gain, and increased browning percentage, although callus diameter was not affected.