外源硝酸钙对水培生菜生长及矿质元素吸收的影响

为有效提高水培生菜产品的营养品质和矿物质含量,试验设置0.1%、0.3%、0.5%3个浓度硝酸钙进行叶面喷施处理,以喷施蒸馏水为对照,对不同处理下生菜生长、产量、品质及矿质元素吸收量进行统计分析。结果表明,硝酸钙叶面喷施处理诱导了SOD、POD、CAT活性的升高。硝酸钙处理28 d,各处理维生素C含量低于对照组,但差异不显著;0.5%处理硝酸盐含量显著高于对照,其他处理与对照组差异不显著;0.3%处理可溶性蛋白、叶绿素含量显著高于对照。外源硝酸钙处理可增加叶片数、根长、根冠比,0.3%处理单株产量升高5.9%,可增加生菜地上部分磷、钾、钙含量,钙元素较对照升高最多,为30.8%,铁升高5.3%,镁下降3.2%。0.1%处理铁、镁含量较对照分别升高30.0%、20.3%。但随着处理浓度的升高镁、铁含量下降,0.5%处理较对照分别下降13.1%、1.1%。随着硝酸钙处理浓度的增加地上部锌逐渐从叶片转移至根,0.5%处理地上部分锌含量最低,为110.1mg·kg-1,较对照下降25.8%。综上,适当浓度的硝酸钙可增加水培生菜钙和部分微量元素含量,增加营养品质,施用过量会影响矿物质元素吸收平衡。本研究结果为指导水培生菜生产过程中应用叶面喷施硝酸钙形成高营养品质,提高微量矿物质元素提供了理论依据。

Effect of Exogenous Calcium Nitrate on Dynamic Growth and Nutrient Absorption of Hydroponic Lettuce

To determine the mineral content of lettuce under calcium nitrate treatment and improve the nutritional quality of lettuce products,0.1％,0.3％,and 0.5％ calcium nitrate was sprayed separately on lettuce foliage and distilled water sprayed as control.The growth index,yield,quality and mineral absorption of lettuce were measured,recorded and statistically analyzed.The results showed that calcium nitrate spraying induced the activities of SOD,POD,and CAT.Calcium nitrate treated 28 days;vitamin C content of 3 treatments was lower than control,but the difference was not significant.Nitrate content of 0.5％ was remarkably higher than that of control,and other treatments had no significant difference compared with the control.0.3％ treatment of soluble protein and chlorophyll content was dramatically higher than that of control.Sprayed calcium nitrate increased number of leaves,root length and root shoot ratio.Under the 0.3％ sprayed condition,the yield increased by 5.9％.What’s more,the ground part of the lettuce,calcium nitrate sprayed increased the content of phosphorus,potassium and calcium.Compared with controls,calcium content of 0.3％ treatment increased 30.8％,iron content increased 5.3％,but magnesium content decreased 3.2％.In 0.1％ treatment,iron and magnesium content increased 30.0％ and 20.3％,respectively.However,with the increase of calcium nitrate,iron and magnesium content of 0.5％ treatment decreased 13.1％ and 1.1％,separately.The higher amount of calcium nitrate concentration,the lower zinc content of ground part of the lettuce,and zinc content of 0.5％ treatment was the lowest between treatments,dropping 25.8％ compared with controls.In conclusion,spraying proper calcium nitrate can increase the content of calcium,trace element and nutrition quality of hydroponic lettuce.The findings could guide to spraying calcium nitrate in hydroponic lettuce production,which provides a theoretical basis for improving the trace mineral elements content and promote the formation of high nutritional quality.