Abstract:

Seeds of four macadamia cultivars ‘YunMac 57’, ‘YunMac 51’, ‘YunMac 41’ and ‘YunMac 58’ were irradiated by 60Co-γ ray at 40 Gy, 120 Gy and 200 Gy with the dose rate of 10 Gy/h. Effects of 60Co-γ ray on seed germination and seedling growth of macadamia were observed. Results indicated that the seed germination of macadamia were inhibited by 60Co-γ ray irradiation, the irradiation dose sensitivity of four cultivars were different. The seed germination rate of ‘YunMac 41’ was increased significantly at 40 Gy, but ‘YunMac 57’ was insensitive to the dose range in this study. The true leaf length, width and area were decreased significantly with the increasing of irradiation dose. The stem length of seedling from the irradiated seed was shorter than CK and the stem diameter bigger, but the variation range varied with different macadamia cultivars.