PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Colocasia and Xanthosoma are widely distributed in humid tropical areas and primarily found in moderate to high rainfall areas. In Indonesia, Colocasia esculenta var. antiquorum (eddoe taro) and Xanthosoma undipes (beneng banten taro) are prominent taro. However, traditional vegetative propagation methods often result in limited phenotypic diversity. Gamma irradiation of embryogenic calli presents a promising approach to induce genetic diversity for taro improvement. This study aimed to assess the radiosensitivity of Indonesian taro explants to gamma-ray irradiation by determining the LD₅₀ value and evaluating the impact of the gamma ⁶⁰Co irradiation dose on the proliferation and growth of taro embryogenic calli. The research adopted a completely randomized factorial design, encompassing eight treatments of Gamma ⁶⁰Co radiation dose ranging from 0 to 27.5 Gy, combined with two treatment media variations on callus formation, with 12 repetitions each. The results showed that gamma-ray irradiation affected callus formation, embryogenic callus proliferation, and the number of globular phases of somatic embryos in both explants. The LD₅₀ for Colocasia esculenta explants was determined to be 7.23 Gy, while that for Xanthosoma undipes explants was 12.84 Gy. These findings underscore the significant effect of gamma-ray irradiation on explants, elucidating its potential to induce mutations and augment genetic diversity in orphan crop species such as Indonesian taro.