Effect of Temperature and Various Pre-treatments on Germination of Hippophae rhamnoides Seeds

This study was carried out to test seed germination responses to temperatures and pre-treatments in Hippophae rhamnoides, which has many abilities in antioxidant activity, soil improvement and erosion control. H. rhamnoides seeds were placed at 10, 15, 20, 25, 30 and 35℃ under light condition. As the results, germination percentage (GP) was the highest at 15 and 20℃, and mean germination time (MGT), germination rate (GR) and germination value (GV) were the highest at 25℃. Quadratic and linear regression model were used to determine the cardinal temperatures such as base (Tb), maximum (Tm) and optimum (To) temperature for germination. In quadratic regression model using PG, Tb, Tm and To was estimated as 0.6, 36.4 and 18.5℃, respectively, and temperature range for germination was 35.8℃. In linear regression model using GR, Tb, Tm and To was estimated as 8.3, 35.4 and 25.3℃, respectively, and temperature range for germination was 27.2℃. Germination properties were investigated after H. rhamnoides seeds were treated by prechilling (1, 2, 4, 6 and 8 weeks), stratification (2, 4, 6 and 8 weeks), solid matrix priming (seed : carrier : water = 5 : 1 : 7, 8, 9 and 10), osmo-priming (-0.25, -0.5, -1.0 and -1.5 MPa) and calcium chloride (CaCl2) -priming (100, 200, 300 and 400 mM). The highest GP was observed in CaCl2 300 and 400 mM treatments, and MGT was the shortest in stratification 6 and 8 weeks treatments. GR and GV were the highest and GP was the second highest when seeds were prechilled for 1 and 2 weeks. Consequently, prechilling 1 or 2 weeks treatment was considered as the appropriate method when we contemplate qualitative and quantitative effects in seedling production.