Effects of ionizing radiation (60Co gamma rays) on growth and morphogenesis ofHaworthia mirabilis,haw. Callus tissue

Summary The effects of γ-radiation on growth and morphogenesis ofHaworthia callus in vitro were determined. The doses ranged from 100 to 5000 rads. Survival, growth pattern, growth rate, and differentiation of vegetative buds and roots in both irradiated and nonirradiated callus were compared. Growth data up to 24 weeks for irradiated and control cultures were analyzed. The dose range between 800 to 2500 rads produced compact callus as compared to the controls which were friable. After 12 weeks all control cultures differentiated vegetative buds with roots, whereas callus exposed to 800 to 2500 rads continued to grow with little or no organogenesis. However, it was observed that the wet and dry weights of callus receiving 1000 to 1500 rads ultimately exceeded those of nonirradiated controls.