Gamma sensitivity of forest plants of Western Ghats

• Preliminary screening for radio sensitivity and classification.
• Biopositive and negative impact of gamma rays on germination and growth.
• Low dose hormesis in radioresistant plants.
• Complete loss of viability in sensitive plants.

Seeds of Artocarpus hirsutus Lam., Garcinia xanthochymus Hook., Saraca asoca Roxb., Rourea minor Gaertn., Pterocarpus marsupium Roxb., Terminalia chebula Retz., Aporusa lindleyana (Wt.) bail., Holoptelea integrifolia Roxb. and Oroxylum indicum (L.) Vent. were collected from different regions of Western Ghats and exposed to different doses of gamma radiation using Co-60 source. The effect of irradiation was examined on germination, growth and vigor parameters. Decrease in the germination and growth attributes with increased dose was observed in A. hirsutus, G. xanthochymus and S. asoca and thus indicating sensitivity of these plants to radiation. In contrast, enhancement in the germination (percentage), vigor and generation of leaves was observed for P. marsupium, T. chebula, H. integrifolia and O. indicum. These plants were classified as radiation tolerant because of the ability of their seedlings to successfully establish under radiation stress. R. minor and A. lindleyana were able to maintain viability up to 100 Gy dose, however, any further increase in the dose found to have negative effect.