Effect Of Ionizing Radiation On Some Characteristics Of Seeds Of Wheat

ABSTRACT Seed irradiation during pre-sowing processes is one of the most effective methods to improve the plant production. This investigation was carried out to determine the effects of ionizing radiation on germination and physiological characteristics of wheat seedlings. Therefore two separate experiments were therefore conducted 1. Using the filter paper method to assess the germination and rate and the initial seedling vigour indices I and II in the laboratory conditions. 2. Following a randomized complete block design with three replications in the field of the Nuclear Research Laboratory IARI New Delhi. Seeds of Wheat plant were irradiated with gamma rays at Control 0 0.1 0.15 0.155 0.16 0.165 0.17 0.175 0.18 0.19 0.20 0.25 kGy on the Cobalt-60 Gamma irradiation chamber GC-5000 dose rate 2.18 kGyh at the Laboratory. Irradiation doses depend on many conditions that involve exposure to the rays type quantity and radiation time and behaviour of the irradiated environment absorption capacity physical chemical and biological modifications and secondary reactions Evangelista 2000. The parameters studied were percent germination plant biomass including root and shoot mass and plant height. To determine these effects seeds were exposed to radiation with time period of 165 247 255 264 272 280 288 296 313 330 and 412 seconds for the irradiated treatment as given above respectively. A dose-dependent increase in percentage emergence in radiated plants up to 0.17 kGy. At higher dose of 190 Gy there was a drastic reduction in physiological characteristics of seedling of wheat. Shakoor et al. 1978 and Khalil et al. 1986 attributed decreased shoot lengths at higher doses of gamma rays to reduced mitotic activity in meristematic tissues and reduced moisture contents in seeds respectively. The study concludes that gamma radiation at a low dose stimulates while a high dose 0.18 kGy and above inhibits plant growth and development of wheat.