Efecto de la irradiación con rayos gamma sobre la morfología de dos cultivares in vitro de malanga (Colocasia esculenta L. Schott)

In Nicaragua, two taro cultivars (Lila and Blanca) (Colocasia esculenta L. Schott) are cultivated, yet neither cultivar exhibits tolerance to biotic or abiotic factors. The crop requires abundant water, and in Nicaragua the rainy season is insufficient to meet water requirements for this crop. Gamma radiation has been identified as a tool to accelerate plant breeding programs. The present study evaluated the effect of gamma ray irradiation as a source of mutation induction in the morphology of two taro cultivars. In vitro plants of Lila and Blanca taro were irradiated with 0 (control), 5, 10, 15, 20, 25 and 30 Gy of gamma rays. The variables evaluated were plant height (cm), leaf number, shoot number, root number, survival percentage, 50% growth reduction dose [DR50] and 50% lethal dose [DL50]. In both cultivars the variables presented a negative correlation with the irradiation doses; as the doses increased, plant height, number of leaves, shoots and roots decreased. The optimal irradiation doses for Lila taro were determined to be 10, 13 and 16 Gy, while for Blanca taro these doses were 20, 25 and 30 Gy. In the case of Blanca taro, 100% survival was recorded in the control and at the 5 and 10 Gy doses. In the case of Lila taro, 100% survival was recorded in the control and at the 5 Gy dose. The LD50 in Lila taro was determined to be 19 Gy, while in Blanca taro, the LD50 was established as 53 Gy.