断氮处理对水培生菜维生素C累积的影响

Effects of Nitrogen-free Solutions on Vitamin C Content in Lettuce Grown Hydroponically

通过温室水培试验,研究了3种断氮处理对生菜各部位叶片维生素C含量的影响。结果表明,与全营养液相比,3种断氮处理可显著提高生菜展开叶叶片中的维生素C的含量,断氮处理2 d时效果已很明显,8 d时维生素C增持效果依然显著。除第4天无氮营养液和蒸馏水处理增加了老叶维生素C含量外,在其他取样时间3种无氮营养液处理对生菜老叶中维生素C含量无显著影响。基于可操作性和成本,建议清水(取代蒸馏水)和氯化钾溶液作为无氮处理液用于采前提高无土栽培叶菜维生素含量。

A glasshouse experiment was conducted to investigate the impacts of three kinds of nitrogen-free hydroponic solutions on vitamin C contents in expanded leaves and old leaves during eight-day treatment period. The results showed that three nitrogen-free hydroponic solutions could increase vitamin C content in expanded leaf blades at all four sampling times （two-day samples to eight-day samples） compared with the full nutrient solution treatment. The emcacies of vitamin C content improvement of three nitrogen-free solution treatments were still effective for eight days under the experimental conditions. However, nitrogen disruption treatment did not improve the vitamin C content in old leaves except at four days later after treatments of nitrogen-free nutrient solution and distilled water. Based on the practical feasibility and cost, tap water （replacing distilled water）, KCl solution were promised to use for improving vitamin C content before harvest.