Effects of temperature on the germination of Elymus nutans seeds

This study was aimed at determing suitable germination conditions for Elymus nutans seeds collected from four altitudes (3 941, 3 528, 3 212 and 2 925 m). These seeds were germinated under different temperatures and light gradients. The results indicated that the suitable germination temperatures of E.nutans ranged from 15 ℃ to 25 ℃. Variable temperature can significantly improve germination uniformity and germination rate. The best combination of variable temperature was 20 ℃/10 ℃, in which germination rate and germination potential increased 20.2% compared with that at 20 ℃. Germination of E.nutans seeds were not sensitive to light conditions. In the lower temperature, seed germination ability from the lower altitude was superior to that from the higher altitude, while in the higher temperature, seed germination ability from the higher altitude was superior to that from the lower altitude. In the intermediate temperature, however, the seed germination performance did not show significant differences among four altitude levels.