Abstract: To find an efficient way to promote seed germination of azaleas, whose seeds were very small and had low germination, self-pollinated seeds from azalea cultivar Zihudie were treated in three ways: 1) water soaking for 6 to 48 h; 2) 100 to 2 000 mg·L^-1 GA₃ soaking for 24 h; 3) cultured in 1/4 MS medium with different combinations of NAA, KT, ZT and GA₃. Then seed germination status of these treatments, including germination time, germination rate and other indicators were compared. The results showed that germination rate of seeds reached 43% when water soaking 24 h and the germination rate increased to 75% when aseptic seeding with 2.0 mg·L^-1 GA₃+0.05 mg·L^-1 NAA. Soaking seeds with 1 600 mg·L^-1GA₃ for 24 h increased the germination rate to 82%, which was 1.82 times as that of the control. Then this GA₃ soaking treatment was set on seeds got from two cross breeding of azalea cultivars which named NO.29 and NO.59. The results showed that when treated with different concentrations of GA₃ for 24 h, germination rate and related index of these two hybrid seeds were superior to those of the controls. Additionally, when the seeds of NO.29 were soaked with 1 200 mg·L^-1 GA₃ for 24 h, the germination rate was 96%. As for NO.59, the germination rate was 95% when the seeds were soaked with 1 600 mg·L^-1GA₃ for 24 h. The seeds germinated 2 and 7 d earlier than the controls, and their germination rates increased 20% and 71% than the controls, respectively. Thus, this treatment especially high concentration of GA₃ soaking was efficient in promoting germination for both self-pollinated seeds and hybrid seeds of azalea cultivars.

Key words: azalea, self-pollinated seeds, hybrid seeds, hormone treatments, germination