Effects of gamma irradiation on germination and physiological parameters of maize (Zea mays) genotypes

Abstract

This study determined the effect of gamma irradiation on the seedling growth parameters and enzymatic activities of gamma irradiated seeds of two maize (Zea mays L.) genotypes. Twelve doses of gamma irradiation ranging from 0.0025 to 2.0 kGy were given to the seeds with the help of 60Co γ-radiation source facility available at NRL, IARI, and New Delhi. Water activity, germination per cent, seedling growth, dry weight of seedlings and enzymatic activity were determined by using the standard procedures and protocols. Data obtained showed that the seedling length increased in lower doses (0.0.005 to 0.1 kGy) of gamma irradiation and reduced on and beyond the 0.2 kGy dose for both the genotypes. Similarly seedling vigor index I reduced on and beyond 0.2 kGy of gamma irradiation dose. The germination per cent and alpha amylase activity was significantly more in lower doses (0.0025 to 0.2 kGy) of gamma irradiation and reduced on 0.3 kGy or beyond for both maize genotypes. Water activity of irradiated seeds did not change significantly.