Effects of exogenous hormones treatments to release seeds dormancy of Setaria sphacelata cv. Narok

Setaria sphacelata cv. Narok is one of the most prominent forages applied in grassland construction and environmental treatment in southern China, which has broad promotion prospects. However, the low seed yield, poor quality and deep dormancy restrict the popularization and utilization of this forage. Soaking treatment with exogenous hormones including GA3, IBA, 6-KT and ETH were applied to break dormancy of Narok seeds from Yunnan Province. The results showed that all of these four different exogenous hormones could break Narok seed dormancy and promote seed germination and seedlings growth with different effects. The treatment with 400 mg·L-1 GA3 soaking for 24 h was the best. The germination energy, germination percentage, germination index and the vigor index was 48%, 54%, 19.46 and 0.015 2, respectively, and increased by 1.18 times, 1.08 times, 1.31 times and 1.14 times compared with the control, respectively. These indices were significantly higher (P＜0.05) than the corresponding indices from control. Effects of the treatment with 450 μL·L-1 ETH soaking for 24 h was the second best. The treatments with 20 mg·L-1 IBA and 5 mg·L-1 6-KT soaking for 24 h also had significant promoting effects (P＜0.05) on Narok seeds germination.