Effect Of Salicylic Acid And Calcium On Seed Germination And Physiological Characteristics Of Pepper Seedlings Under Low Temperature Stress

The low-temperature-sensitive and tolerance crops --pepper seedlings were used as material in the test, the effect of calcium and Salicylic acid on chilling of pepper seedlings was studied. The results are summarized below:1. The effects of low temperature stress on germination of pepper seeds were extremely distinct influence, with the prolonged time of low temperature stress, the inhibition on germination increased significantly. The germination rate,germination energy and the length of seedlings were all descend, and the relatively conductance rate increased. Different concentrations of Salicylic acid and Ca2+can mitigate low temperature stress in some degree. And the conductance rate was less than comparison, meanwhile reduced the germination rate and the length of seedlings.2. 0.72mmolL-1 Salicylic acid and 10mmolL-1 Ca2+ can enhance the activity of super-oxide dismutase (SOD), peroxidase (POD) and catalase (CAT).The activities of antioxidant enzymes SOD, POD and CAT in 0.72mmol/L Salicylic acid and 10mmol/L Ca2+-treated pepper seedlings were all higher. Reduce the content of MDA and cell membrane permeability.3. 0.72mmolL-1 Salicylic acid and 10mmolL-1 Ca2+can obviously enhance the content of soluble sugar and proline in Pepper seedlings under low temperature stress. The result showed that: the Signal System of Ca2 +and Salicylic acid participate in the Synthesis of pepper seedlings during cold penetration.4. Fv/Fm,Ñ„PSâ…¡,qP and Fv '/Fm' in Pepper seedlings were reduced to varying degrees under low temperature stress. 0.72 mmolL-1 Salicylic acid and 10 mmolL-1 Ca2+ can obviously enhance the content of Fv/Fm,Ñ„PSâ…¡,qP and Fv '/Fm'. They were significantly higher than CK.5. Pn,Tr and Gs in Pepper seedlings were reduced to varying degrees under low temperature stress, the content of Ci raise. 0.72mmolL-1 Salicylic acid and 10 mmolL-1Ca2+can obviously raiser the content of Pn,Tr and Gs than CK, The cause of reduction of net photosynthetic rate in pepper seedlings under low temperature stress might be mainly non-stomata limitation. 6. 0.72mmolL-1 Salicylic acid and 10mmolL-1 Ca2+ have higher Regulation in low-temperature-sensitive species than low temperature stress-resistant varieties.