Seeds sterilization and germination
Alfalfa cultivar ‘Zhongmu No. 1’ was used in this study. The mature seeds were soaked in 50% sulfuric acid for 10 minutes, rinsed 5 times with sterile water. Then sterilizing with 5% sodium hypochlorite for 40 minutes, and then washed with sterile water for 5 times. The sterilized alfalfa seeds (100 seeds/ plate) were germinated on filter paper soaked with sterile water containing 0 μM ABA or 50 μM ABA in an incubator with a photoperiod of 14h/ 10h (day/night), 25℃ for 7 days. The number of germinated seeds was counted. Three biological replicates were carried out.