Sensitivity and Potential of Terminalia tomentosa Roxb towards Different Gamma Irradiations Exposure Regimes at Early Seedling Growth Phase

The seeds of Terminalia tomentosa Roxb were collected from Achanakmar Amarkantak Biosphere reserve, Central India. The air dried seeds were exposed to different gamma irradiations doses (10kR, 20kR, 40kR and 60kR) in Continuous (C) and Fractionated (F) pattern using 60 Co source. The sensitivity and potential of germination, growth and vigor parameters of Terminalia tomentosa under influence of different gamma irradiation doses was examined in the present study. Increase in the germination and growth parameters under the lower continuous and fractionated doses of gamma irradiation indicate the potential of the lower doses of gamma irradiation in the early growth improvement of Terminalia tomentosa. In contrast, the higher doses of gamma irradiation have a retardant effect on germination, growth and vigor parmeters thus the tree show higher sensitivity towards these gamma irradiation doses. It was observed that the fractionated dose pattern cause more inhibition in different germination and growth parameters than the continuous doses. The 10kR continuous dose level showed the best acceptability and maximum enhancement in different growth and germination parameters. The LD-50 values varied among the different growth parameters and it was seen that the leaf formation and radicle were the most sensitive parameter. The PCA indicate and confirm the significance of different continuous and fractionated gamma irradiation doses in altering the germination and early growth parameters of Terminalia tomentosa.