Morphophysiological and biochemical alterations in Ricinus communis L. seeds submitted to cobalt60 gamma radiation

Abstract

This study aimed to evaluate the radiosensitivity of castor bean seeds after applications of different doses of Cobalt 60 gamma radiation. Seeds were pre-soaked for 24 hours in distilled water and then irradiated with 50, 100, 150, and 200 Gy, except the control. Sowing was performed in trays, which contained soil as substrate and were maintained in a greenhouse. The electrical conductivity, emergence, emergence speed index, growth parameters and activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, and catalase) were evaluated in the leaves and roots of castor bean seedlings. Gamma radiation did not affect the electrical conductivity of the seeds; however, at a dose of 200 Gy, the emergence and emergence speed index of the seedlings was negatively affected. An analysis of the morphophysiological parameters revealed a reduction in seedling size as the radiation dose increased. There was a significant increase in superoxide dismutase and ascorbate peroxidase activities at higher radiation doses in the leaves, but not in roots. Thus, the analysis of all the variables suggests a response pattern as to the morphophysiological and biochemical changes of castor bean seedlings due to the increase of gamma radiation, which may serve as a tool for generating greater genetic variability.

Ionizing Radiation: Effective Physical Agents for Economic Crop Seed Priming and the Underlying Physiological Mechanisms

“…With excellent penetration abilities, they can easily penetrate through glass and plastics, but they can be effectively blocked with the proper thickness of concrete or lead plate. γ-rays usually interact with the atoms or molecules in the plant cells, and they produce free radicals to influence the essential cells’ components and affect the morphology, anatomy, biochemistry, and physiology differentially, and together, they accelerate the seed germination, stimulate seedling growth, increase the production of secondary metabolites, and alleviate the biotic or abiotic stress effects [ 13 , 44 , 66 , 67 , 68 ]. The positive impact of low-dose γ-rays has been reported by Akshatha, and compared to the controls, 25 and 200 Gy doses of γ-rays enhanced the rate of seed germination in Holoptelea integrifolia and Oroxylum indicum , meanwhile, in the case of Terminalia chebula , irradiation with a 25 Gy dose also produced the low-dose hormesis phenomenon [ 35 ].…”

Response of radioactive cobalt (60Co) teletherapy on M1 plants of Capsicum chinense Jacq

“…Several researches on the stimulative effects when using gamma rays as induced mutagens were reported. Recently, low doses of gamma-rays of seed treatment resulted significant effects on germination, shoot and root systems of Chilli (Omar et al, 2008) [9] , Wheat (Melki and Marouani, 2010) [10] , Physic nut (Sangsiri et al, 2011) [11] , Rice (Harding et al, 2012) [12] , Maize (Marcu et al, 2013) [13] , Pigeon pea (Neelum et al, 2014) [14] , Chick pea (Umavathi and Mullainathan, 2015) [15] , Lathyrus (Beyaz et al, 2016) [16] , Castor bean (Lopes et al, 2017) [17] , Soybean (Kusmiyati et al, 2017) [3] . However, the impact of gamma rays on Capsicum chinense Jacq.…”

Mutagenic effects of gamma rays on soybean (Glycine max L.) germination and seedlings

“…Several research on the stimulative effects when using gamma rays as induced mutagens were reported. Recently, low doses of gamma-rays of seed treatment resulted significant effects on germination, shoot, and root systems of wheat [13], physic nut [14], rice [15], maize [16], pigeon pea [17], chick pea [18], lathyrus [19], castor bean [20].However, the impact of gamma rays on soybean cv. Dering 1 is still unknown.…”