Impact of Cobalt-60 Gamma Irradiation on Growth, Development, and Morphology of <em>Acalypha hispida</em> (Cat&rsquo;s Tail Plant)

Abstract

Gamma irradiation-induced mutagenesis has been utilized to improve many genotypes of crop species. Mutation induction has been identified as a significant method for the production of genetic variation in flowering plants. Hence, a series of experiments were conducted in a completely randomized design at the University of Colombo Institute for Agro-technology and Rural Sciences, Hambantota, Sri Lanka, to evaluate the influence of gamma rays on the mutagenicity of Acalypha hispida. The rooted cuttings were subjected to various dosages of Cobalt-60 gamma irradiation, including 0, 20, 25, 30, 35, and 40 Gy. Based on the findings, a second experiment was carried out in which the plants were exposed to 0, 45, 50, 55, 60, and 65 Gy gamma irradiation dosages. Treated plants were maintained inside a shade net house (30% shade) and morphological changes in plants, survival %, plant height, number of leaves, inflorescence length, and mutation % were recorded. Plants that showed improved characters were multiplied and observed the character expression in the second generation. Further, attempts were made to combine the improved characters into a single plant. There were significant differences in plant height and number of leaves but not in survival % and inflorescence length in experiment one. Further, a significant difference was observed in measured variables survival %, plant height, number of leaves, and inflorescence length in experiment two. A gradual reduction was observed in survival percentage, plant height and inflorescence length with the increase in gamma irradiation dose. Treated plants showed narrowed and malformed leaves but those were not persisted and discontinued. But, irradiated plants produced colour changed (pink and white), partial and no blooming inflorescences which was persisted in the second generation too. Hence, it could be stated that treating the A. hispida plants with gamma radiation has the potential to create mutation in plants.