Effect of gamma irradiation on the morphological and physiological variation from In vitro individual shoot of banana cv. Tanduk (Musa spp.)

Abstract

Inducing genetic and morphological variation through conventional method is very difficult. Therefore, mutation induction through in vitro technology brings numerous advantages over the conventional breeding. Thus, the individual shoots (1 ~ 2 cm) were irradiated with gamma rays (10 ~ 70 Gy). The result revealed that the explants treated with higher doses (40, 50, 60, and 70 Gy) showed deleterious effects of ionizing radiation. The highest survival rate among γ treated explants recorded was 71% in 10 Gy treatments while the lowest survivality was 15% in 70 Gy. Lethal dose 50% (LD50) dose was found to be 33 Gy. In the in vitro condition, rooting reponse showed that increase in gamma irradiation dose resulted in the inhibition of root growth. Meanwhile, non-treated explants had the best rooting ability with the maximum number of root per explant (20) within a short period of time (6 days), with the highest root length of (15.1 cm). The longer period in rooting (12 days) and lowest number of root per explant (8) with shortest root length (10.1 cm) were recorded at 30 Gy treatment. The highest shoot length (13.6 cm) was observed at control treatment and the shortest shoot length (10.4 cm) was observed at 30 Gy. In the nursery, lowest leaf number (5) was observed at 30 Gy compared with other treatments. The highest chlorophyll content (49.8) was recorded at 10 Gy treated seedling. Irradiated explants with 10 Gy found to be superior over the control treatment and had positive effects in main growth parameters such as chlorophyll content.