不同氮、钙营养对菠菜安全品质与抗氧化酶活性的影响

Effects of nitrogen and calcium nutrition on safety quality and anti-oxidative enzyme activities of spinach

通过溶液培养研究了氮、钙营养对菠菜生长、安全品质和抗氧化酶活性的影响。结果表明,在Ca2+浓度相同时,菠菜在供N浓度为12 mmol/L时产量最高;相同供N水平下,Ca2+浓度为5 mmol/L时,菠菜可获得较高产量。菠菜可食部位的硝酸盐含量随着N和Ca2+浓度的升高明显上升。当N浓度为8 mmol/L时,菠菜可食部位可溶态草酸含量最低;在Ca2+浓度为5 mmol/L时,草酸总量最低。N浓度相同时,以5 mmol/L Ca2+处理的叶片POD活性最低;当供N浓度为8 mmol/L时,5 mmol/L Ca2+处理的叶片SOD活性最高,而CAT活性则随着N和Ca2+浓度的提高而显著下降。相同Ca2+浓度下,丙二醛的含量随着供N浓度的升高而明显增加;而在相同N水平下,Ca2+浓度为5 mmol/L处理的叶片丙二醛含量最低。叶片游离脯氨酸的含量均随着Ca2+浓度的增加而明显降低,低N处理的脯氨酸含量也较低。说明在本试验条件下,N浓度为8 mmol/L和Ca2+浓度为5 mmol/L,是菠菜生长较适宜的氮、钙浓度。

A hydroponic experiment was carried out to study the effects of nitrogen and calcium nutrition on the growth, safety quality and antioxidative enzyme activities in spinach. Results showed that spinach achieved the highest biomass at the rate of 12 mmol/L N supplied with the same rate calcium. With the same N supply, spinach achieved higher yield when 5mmol/L Ca2^＋ was supplied. Nitrate content and Ca2^＋ concentrations in edible parts of spinach increased with N. At 8mmol/L N concentration, soluble oxalate content in edible parts of spinach was lowest, while total oxalate was lowest with 5 mmol/L Ca2^＋ . With the same N supply, POD activities of spinach leaves were lowest supplied with 5mmol/L Ca2^＋ . SOD activities of leaves were highest when N concentration was 8 mmol/L and Ca2^＋ level was 5mmol/L. CAT activities markedly decreased when N and Ca2^＋ concentrations were increased with the same N level. Supplied with the same calcium concentrations, MDA content increased with the increase of N concentrations, while MDA content of 5 mmol/L Ca2^＋ was the lowest with the same N supply. Proline contents in leaves increased markedly when Ca2^＋ concentrations were increased and those of low N treatments were lower. In conclusion, 8 mmol/L N and 5 mmol/L Ca2^＋ were the proper concentrations of N and Ca nutrition for the growth of spinach based on results from this experiment.