Germination Characteristics and Secondary Metabolism Regulation of Scutellaria baicalensis Georgi Seeds under Different Temperatures

[Objective] To study the germination characteristics and secondary metabolism of Scutellaria baicalensis Georgi seeds under different temperatures.[Method]The activities of superoxide dismutase（SOD）and peroxidase（POD）were determined with lactoflavine-NBT method and guaiacol-colorimetry assay,respectively.The catalase（CAT）,ascorbate peroxidase（APX）,phenylalanine ammonia-lyase（PAL）and cinnamic acid 4-Hydroxylase（C4H）were determined with ultraviolet spectrophotometry.The secondary metabolites were detected by High Performance Liquid Chromatography（HPLC）.[Result]The germination percentage,germination potentiality and germination index were seriously affected by low or high temperature.The proper germination temperature was 20-25 ℃.The activities of SOD,POD and CAT were significantly decreased as comparison to suitable temperature.The activities of PAL and C4H were also significantly decreased as comparision to suitable temperature which was accordance to the secondary metabolites.There was a positive correlation between the flavonoids content and the PAL and C4H activity（r=0.956,r=0.951,P0.05）.[Conclusion]The quality of the skullcaps could be improved by improving the activity of PAL and C4H.The proper temperature for the seed germination and the formation of secondary metabolites was 20 ℃.

Effect of GA_(3) Concentration and Soaking Time on Seed Germination Characteristics of Blueberry

This study aims to explore the effect of GA_(3) concentration and soaking time on seed germination characteristics of blueberry.To be specific,big(B),medium-sized(M),and small(S)blueberry seeds were soaked in 0,100,200,and 300 mg/L GA_(3) solution for 18 h and 200 mg/L GA_(3) solution for 0,24,and 48 h,respectively.The results showed that 300 mg/L GA_(3) had significant effect on the germination of B and M seeds(P<0.01)and enabled the germination 4~5 d and 7~8 d earlier,respectively.Soaking with 200 mg/L GA_(3) for 24 h was conducive to the germination of B and M seeds(P<0.05).However,GA_(3) concentration and soaking time had no obviously promoting effect on the germination of S seeds.The interactions between GA_(3) concentration and seed size and between soaking time and seed size were significant(P<0.01).

Germination Characteristics of Hordeum brevisubulatum Seeds in Different Conditions

[ Objective] To study the germination characteristics of Hordeum brevisubulatum seeds in the Songnen Plains of China under different conditions and find out the optimum conditions for germination. [ Method] A total of five variable temperatures including 15/25, 20/30, 15/30, 20/25 and 15/20 ℃, five concentrations of sodium chloride solutions including 0, 75, 85, 95 and 105 mmol/L, and five concentrations of CS2 strain （the A values were 0, 0.500 0, 0.050 0, 0.005 0 and 0.000 5, respectively） were studied by orthogonal experimental design. [ Result] The germination rate, germination energy and germination index were significantly （ P 〈 0.05） affected by the temperature and sodium chloride concentration, but rarely affected by the CS2 strain concentration. Moreover, the germination rate, germination potential and germination index were all decreased with the increasing of sodium chloride concentration. [ Conclusion] The optimal germination conditions of Hordeum brevisubulatum are as follows： temperatures of 15/25 ℃ and 15/30℃, 0 mmoVL of sodium chloride concentration.

Effect of Water Supply on Seed Germination of Soil Seed-bank in Desert Vegetation

在温室条件下 ,进行了水涝和保湿 2种水分供应试验。结果表明 ,在土壤种子库中 ,有 3种植物的种子在水涝条件下的萌发数量明显较大 ;9种植物在保湿条件下的萌发数量明显较大 ;18种植物在 2种水分供应条件下的萌发数量没有明显差异。当植物的土壤种子密度较低时在不太合适的萌发条件下表现为不存在。研究结果强调在进行土壤种子库分析之前预备萌发试验的必要性。同时也揭示出利用一种标准的水分供应处理方法去分析来自不同生境土样里种子库的危险性。