Ascertaining gamma ray dosage sensitivity of In vitro cultures in banana cv. Ney Poovan (Musa AB)

In a vegetatively propagated and parthenocarpic crop like banana, the mutation breeding method offers considerable scope to create genetic variability for crop improvement. It is necessary to determine the LD₅₀ dose for optimizing the radiation dosages when gamma rays are used for mutation induction. In the present study, in order to fix the LD₅₀ dose for explants cultured in vitro in cv. Ney Poovan, in vitro shoot tips were subjected to five different doses of gamma rays ranged from 5 to 25 Gy. Proliferating multiple shoots were subjected to five different doses of gamma rays ranged from 2 to 10 Gy. The results revealed a linear and significant reduction in the survival percentage, shoot length and number of shoots with increasing levels of gamma irradiation doses in both the category of explants. The probit curve based analysis on mortality of treated explants revealed that LD₅₀ dose of gamma rays to be 18.77 Gy for cultured shoot tips and 6.97 Gy for proliferating multiple shoots under in vitro.