钙对盐胁迫下油用向日葵幼苗光合生理特性的影响

Effects of Supplemental Calcium on Photosynthetic Characteristics of Oil Sunflower Seedlings

研究了CaCl2调控对盐胁迫条件下油葵幼苗耐盐性的影响，旨在提高油葵的抗盐性，扩大油葵的种植面积，为综合利用沿海滩涂提供理论依据。以杂交油葵G101（Heliamhus annuus L．）为试验材料，采用砂培法培养油葵幼苗至四叶两心期，用不同浓度CaCl2（4，9，19，29mmol/L）对NaCl（150mmol/L）的盐胁迫进行调控，对照为1／5Hoagland营养液和含150mmol／LNaCl的1／5Hoagland营养液。研究了钙对盐胁迫下幼苗油葵生长速率、净光合速率、SOD、CAT、POD活性和MDA含量影响。结果显示：150mmol／LNaCl的盐胁迫下油葵幼苗生长速率明显降低。在5～30mmol／L钙处理后，能促进盐胁迫下植物的生长，提高油葵幼苗生长速率，幼苗叶片的净光合速率也显著增加，尤其20mmol/L钙处理后净光合速率高于CK。盐胁迫下10mmol/L钙离子可明显提高超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（cAT）的活性，降低植株体内丙二醛（MDA）的含量。综合CaCl2调控对NaCl胁迫下的幼苗各项生理指标的情况，初步认为150mmol/L NaCl胁迫下，10mmol/LCaCl，可以有效调控油葵幼苗植株生长。

In order to improve the salt-tolerance and to increase planting area of oil sunflower, CaCl2 regulation on salt-tolerance of oil sunflower under salt stress was studied, providing the theory basis for the comprehensive utilization of coastal beaches. The hybrid oil sunflower G101 as test materials was cultured in Hoagland nutrient solution. At the stage of four leaves, under salt stress the seedling was treated with 4,9,19,29 mmol/L CaCl2 respectively. 1/5 Hoagland nutrient solution and 1/5 of Hoagland nutrient solution containing 150 mmol/L NaC1 was used as control. The effects of different CaCl2 concentrations on seedling growth rate, net photosynthetic rate （Pn）, superoxide dismutase （SOD）, catalase （CAT） ,peroxidase（POD） activity and malonyldialdehyde （MDA）content of oil sunflower seeding under salt stress were measured. The results showed that oil sunflower seedling growth rate was decreased significantly under salt stress with 150 mmol/L NaC1. However, treated with 5 - 30 mmol/L calcium, oil sunflower seedling growth rate were all improved and the net photosynthetic rate（Pn）of oil sunflower increased significantly. Especially under salt stress with 20 mmol/L calcium, the Pn were higher than that of control.under the condition of salt stress with 10 mmol/L calcium,the activity of SOD, POD and CAT were all increased and the MDA content were decreased in oil sunflower seeding. Therefore, based on the results, 10 mmol/L CaCl2 was considered as optimal concentration for regulating plant growth effectively under the salt stress with 150 mmol/L NaCl at seedling stage of oil sunflower.