Ferid Abdulhafiz, Fatimah Kayat, Suhana Zakaria

Faculty of Agro-Based Industry, University Malaysia Kelantan, 17600, Jeli, Kelantan, Malaysia

 Abstract

Improvement of banana through conventional method have been very difficult due to ploidy and sterility of most popular cultivars. Hence, given the difficulties in conventional breeding, mutation breeding was attempted to induce variability and obtain improved banana varieties. Therefore, banana cv. Tanduk shoots meristem (1.5 x 1.0 cm) were exposed to γ rays at doses ranging from 10-70 Gy. Subculture was conducted up to four cycle followed by induction of rooting. The radio-sensitivity of in vitro shoots towards radiation was assessed through the percentage of the explants that survived the treatment. The highest survival rate (74%) among γ treated explants recorded was in 10 Gy treatment and the lowest survivality (20%) was in 70 Gy. The lethal dose (LD₅₀) which had caused 50% mortality to the irradiated material was found to be 37 Gy. The result on shoot growth showed that the highest shoot number (5) per explant recorded at radiation dosage of 20 Gy, followed by 3 shoots per explant at a dosage of 10 Gy and  highest shoot length (3.43 cm) was observed at 10 Gy followed by 20 Gy and 30 Gy treatment caused significant reduction in shoot length. Similarly, 10 Gy induced maximum root length, whereas explants irradiated with 20 Gy and 30 Gy caused the reduction in root length significantly. Gamma rays at the lower dosage of 10 and 20 Gy imposed a significant impact on shoot growth and 30 Gy caused reduction in growth. Hence, the present research was conducted to study the effect of γ radiation on banana plant, while observing growth traits in γ irradiated explants. 

Keywords: Mutation breeding, In vitro mutagenesis, LD₅₀