Red rice cv. Barak Cenana is a local Indonesian rice which is widely planted in Tabanan Regency, Bali. Barak Cenana red rice has potential as a functional food because it contains a lot of nutrients. However, this rice has an unfavorable character, such as long harvest time so that it can only be harvested once a year, and tall stature that causes plants to lodge easily, reducing its productivity. This study aims to determine the effect of gamma rays on growth and development as well as changes in character to obtain mutants plants that have better character. In this research, Barak Cenana seeds were irradiated using gamma rays with irradiation doses of 100 gy, 200 gy, 400 gy, and 800 gy. Furthermore, radiated seeds were planted in the greenhouse and characterized during the vegetative and generative phases including shoot length, harvest time, chlorophyll content, the number of productive tillers, the number of grain contents, the weight of 1,000 seeds, and the polymorphism profile using Random Amplified Polymorphic DNA Analysis (RAPD). The results of this study indicate that all radiation doses produce plants with random characters. Mutations using gamma rays at doses of 100 gy and 400 gy produced plants with better phenotypic characters than wild-type that is shorter plants, shorter harvest times, and more grain content. In addition, the results of the RAPD analysis confirm that there are genetic changes in irradiated rice. This mutants has the potential to reproduce germplasm and to obtain the next generation of mutants that have higher productivity and shorter plant heights.

“Barak Cenana” is one of the local red rice (Oryza sativa) with high economic value due to its nutrient content. Some of the agronomic characters such as tall shoot, low number of tiller, and late harvesting are drawbacks to improving production. Ethyl Methyl Sulphonate (EMS) is a chemical mutagen widely used to improve rice characters by mutation breeding. The present research aims to investigate the EMS concentration suitable to induce mutation in Barak Cenana and observe the mutagenesis effect of EMS on some agronomic characters of Barak Cenana. For those purposes, mature seeds of Barak Cenana were treated with various concentrations of EMS (0.25, 0.5, 0.75, 1.0, and 1.1 %) for 24 hours. Seed germination, plant growth, some agronomic character related to productivity were compared to untreated rice. EMS reduced and delayed seed germination and inhibit shoot and root growth in early vegetative stage. The ability of EMS to reduce and delay seed germination and inhibit shoot and root growth were doses dependent. EMS concentration of more than 1.0% was lethal for Barak cenana and EMS concentration at 0.75% was able to reduce rice productivity by increasing seed sterility. EMS concentrations between 0.25 and 0.5% with 24 h of soaking are suitable for inducing mutagenesis in Barak Cenana. Additionally, some mutants with distinct morphology such as sterile plant, semi-dwarf, high tillering capacity, and high chlorophyll contents were produced in this research.