γ-氨基丁酸对生菜硝酸盐含量和营养品质的影响

Effects of exogenous γ-aminobutyric acid on nitrate content and quality in lettuce

以美国‘大速’不结球生菜为材料,在水培条件下采用浸种、叶面喷施、营养液添加3种方法,研究了不同浓度γ-氨基丁酸(GABA)对植株生长和营养品质的影响。结果表明:3种施用GABA的方法均可促进生菜的生长,并通过提高硝酸还原酶(NR)活性降低了体内硝酸盐含量,提高了生菜品质;但不同施用方法均存在浓度效应,其中浸种处理、叶面喷施、营养液添加GABA的浓度分别以5.00、100、2.50mmol/L效果较好,在最适宜浓度下对生长和品质指标综合分析认为,营养液添加2.50mmol/L GABA处理的效果最好。

In this paper, the effect of different concentrations of γ-aminobutyric acid （GABA） on the growth and quality of lettuce （non-heading lettuce variety ‘Dasu’ under hydroponics） under three different GABA application methods including soaking, leaf spraying and applying in nutrient solution was investigated. The results showed that all the three methods promoted the growth of lettuce, as well as decreased the nitrate content and improved the quality through increasing the nitrate reductase （NR） activity. But there existed differences among the three applying methods and different GABA concentrations, among them, the better GABA concentrations of soaking, leaf spraying and application in nutrient solution were 5.00, 100 and 2.50 mmol/L, respectively. But exogenous application of 2.50 mmol/L GABA in nutrient solution was found best both in promoting plant growth and improving quality among the three.