Effects of Low Temperature and Variable Temperature on Seed Germination Characteristics of Setaria sphacelata

In order to determine the effects of low temperature and variable temperature on seed germination of Setariaspora acelata cv. Narok. The germination experiments of S. acelata seeds under different low temperature and variable temperature were conducted and the germination rate, germination potential, germination index and vigor index of the seeds were calculated. The results showed that the germination rate and vigor indexes of seeds stored at 4 ℃ for 1, 3, 5 and 7 days increased with the extension of time, and low temperature treatment could break the dormancy of S. acelata seeds to a certain extent. Meanwhile, the seed germination rate, germination potential, germination index, vigor index and bud length are the highest after 5 day alternate treatment of 4 ℃ for 12 h and 25 ℃ for 12 h, and these indexes were 70.67%, 59%, 13.17, 0.014, and 3.503 cm respectively, which were 2.44, 2.16, 3.17 and 3.5 folds higher（p＜0.05） these in control group. The results showed that this was the best technique for effectively breaking the dormancy of S. acelata seeds.