增铵营养对番茄植株伤流液组分及含量的影响

在总氮(N)浓度相等的条件下,研究全硝营养(100% NO3-)和25% 增铵营养(NH4+∶NO3- = 25%∶75%)对开花期和幼果期番茄植株伤流液各组分含量的影响.结果表明,增铵营养显著增加幼果期伤流液中 K的含量,对Ca、Mg、P元素含量没有显著影响;增铵营养下伤流液中 NO3- 的含量下降、NH4+ 含量增加,氨基酸、苹果酸等的含量均显著增加,氨基酸/硝态氮含量之比显著提高,表明喜硝作物适当增铵不仅能够提高根系活力,显著促进K的吸收以供果实发育之需,而且提高了植株整体同化N素的能力.

Effects of enhanced ammonium nutrition on composition and content of tomato xylem sap in two growing stages

The xylem sap was collected in two growing stages to investigate the effects of enhanced ammonium nutrition (25% replacement of NO3--N by NH4+-N) on the contents of NH4+, NO3-, Ca, Mg, K, P, soluble carbohydrate, amino acid, and organic acids during tomato maturation. The results showed that the contents of K, NH4+, amino acid, soluble carbohydrate and malate, the ratio of amino acid content to NO3- in xylem sap increased significantly under enhanced ammonium nutrition in young fruit stage, while NO3- content decreased significantly. No significant effect on the contents of Ca, Mg and P, which indicated that comparing to the single nitrate in solution, enhanced ammonium nutrition could not only improve the root activity in absorbing enough K to meet the requirement of fruit development, but also increase the ability of N metabolism.