Sensitivity of Albizia lebbek Seeds to Gamma Rays

The dry seeds of A. lebbek were treated with 20, 40 and 80 kR of Continuous and Fractionated exposures, from Co⁶⁰ source. Of the two treatments, the higher Fractionated dose both delayed the germination and reduced the Germination Value as well as the Germination Energy Index, in comparison to the Continuous ones. As the dose rate increases, the radicle and hypocotyl length gets stunted and at 80 kR level, the radicle got highly reduced. The length of the shoot and pianule number per seedling also decreased in the same pattern. Contrastingly, the higher doses of grmma rays augmented the size of the cotyledonary leaves as well as their fresh and dry matter production. In general: (a) Fractionated dose proved more potent in retarding the vigour of the seedlings and (b) the radicle was found to be most sensi iv part of the seedling as compared to the others.