外源钙对盐胁迫下马铃薯试管苗生长和相关生理特性的影响
Effects of Exogenous Ca(NO3)2 on Growth and Physiological Characteristics of Potato Test-tube Seedlings under Salt Stress

采用组织培养方法，研究了外源硝酸钙对盐胁迫（100 mmol/L NaCl）下马铃薯试管苗生长及相关生理指标的影响。结果表明：盐胁迫下试管苗生物量显著下降，叶绿素质量分数、根系活力和抗氧化酶活性显著降低，脂质过氧化指标丙二醛（MDA）质量摩尔浓度显著增加，试管苗生长受抑制；适量的硝酸钙（10 mmol/L）能在一定程度上缓解盐胁迫对马铃薯试管苗生长的抑制，提高根系和叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性，使之维持在较高的水平，降低MDA质量摩尔浓度和细胞膜透性，增强根系活力及增加试管苗叶绿素质量分数。可见，适量的外源钙可通过促进盐胁迫下试管苗内抗氧化酶活性的提高，降低膜脂过氧化水平，增强光合能力，缓解盐害对马铃薯试管苗生长的抑制作用，诱导其耐盐性的提高。
Effects of exogenous Ca(NO3)2 on growth and physiological characteristics of potato test-tube seedlings under salt stress(100 mmol/L NaCl) were investigated by tissue culture in this paper.Under 100 mmol/L NaCl，biomass of potato test-tube seedlings declined significantly, chlorophyll content, root activity and antioxidant enzymes activities decreased significantly,molality of lipid peroxidation index the malondialdehyde (MDA) increased significantly, which caused growth inhibition of test-tube seedlings. Modest amount of calcium obviously alleviated inhibition of the seedlings growth under salt stress to certain extent, significantly enhanced activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the leaves and roots of potato test-tube seedlings under salt-stress and maintained it at a high level, enhanced chlorophyll molality and root activity but reduced MDA molality and permeability of cell membrane. The results showed that suitable concentration of exogenous calcium alleviated the inhibition of potato test-tube seedlings under salt stress and reduced salt tolerance by promoting the activities of antioxidant enzymes, the level of membrane lipid peroxidation, enhanced photosynthesis.