RADIOSENSITIVITY OF <em>ALBIZIA</em> <em>PROCERA</em> TO ACUTE AND FRACTIONATED GAMMA IRRADIATION AT TWO MOISTURE LEVELS

Abstract

Radiosensitivity of Albizia procera was calculated by exposing the seeds to acute and fractionated doses (0, 200, 400, 800, 1200 and 1600 Gy) of gamma rays at two moisture levels (6.5% and 48%). ED_50/20 (effective dose) was estimated for seed germination, survival, growth and biomass of seedlings. Chromosomal aberrations were also scored at mitotic anaphase. The number of abnormal cells increased with the increasing doses of gamma rays. Presoaked seeds were more sensitive to gamma rays than those air-dried. ED_50/20 doses of dry seeds under acute irradiation were 540 Gy and 770 Gy for shoot and root lengths respectively. Corresponding values for presoaked seeds were 135Gy and 140 Gy respectively. The fractionated mode of irradiation showed comparatively more reductions in values of different parameters than acute irradiation for both dry and presoaked seeds of Albizia procera. This information could be of significance in further planning mutation breeding strategies and changing the spectrum of induced mutations by altering the mode of irradiation and moisture level of seeds.