钙对盐胁迫下小金海棠幼苗生物量及抗氧化系统的影响

本文以1/2Hoagland营养液栽培的小金海棠为试材, 研究70 mmol·L-1的NaCl胁迫下, 钙对小金海棠幼苗生物量、超氧自由基（O2 ）产生速率、丙二醛（MDA）含量、电解质相对渗透率、抗氧化酶（SOD、POD、CAT和APX）活性及可溶性蛋白含量的影响。结果表明, 盐胁迫下, 小金海棠幼苗生物量显著低于对照, 根系和叶片的O2 产生速率、MDA含量、电解质相对渗透率、抗氧化酶活性及可溶性蛋白含量显著高于对照。盐胁迫下, 与不加钙处理相比, 加钙处理显著降低了小金海棠幼苗O2 产生速率、MDA含量及电解质相对渗透率, 显著提高了生物量、抗氧化酶和可溶性蛋白的含量, 10 mmol·L-1 CaCl2处理的效果显著好于30 mmol·L-1处理的。综上可知, 盐胁迫下小金海棠幼苗的生长受到抑制, 外源施钙可以减轻盐胁迫对幼苗造成的伤害, 提高幼苗对盐胁迫的适应能力。

Effects of Calcium on Biomass and Antioxidant Systems in Seedlings of Malus xiaojinensis under Salt Stress

In this experiment, Malus xiaojinensis cultured in 1/2Hoagland nutrient media was used as test material. The biomass of seedlings of M. xiaojinensis, the superoxide （O2） production rate, malondialdehyde （MDA） content, electrolytic leakage, activities of antioxidant enzymes （SOD, POD, CAT and APX） and soluble proteins content in seedlings of M. xiaojinensis were determined to study the possible effects of calcium on plant under salt stress （70 mmol·L-1 NaCI）. The results showed that, under salt stress, the biomass of seedlings was significantly lower than that in the control, and the O2 production rates, MDA contents, electrolytic leakages, activities of antioxidant enzymes and soluble protein contents in roots and leaves were significantly higher than those in the control. Compared with the absence of calcium from nutrient media, the treatments of calcium significantly reduced the O2 production rate, MDA content and electrolytic leakage, and increased the biomass, activities of antioxidant enzymes and soluble protein content in the seedlings of M. xiaojinensis under salt stress. The addi tion of 10 mmol·L-1 CaCl2 showed a better effect than 30 mmol·L-1 CaCl2 on the salt tolerance of the seedlings. So, it could be concluded that salt stress inhibited growth of seedlings in M. xiaojinensis, and the addition of exogenous calcium could reduce the salt damages to seedlings and improve its salt tolerance.