【作者】 董园园；

【导师】 沈其荣；

【作者基本信息】 南京农业大学 ， 植物营养学， 2006， 硕士

【摘要】 本研究以常规番茄21世纪宝粉为材料，通过盆栽试验研究了增铵营养对番茄生物量、品质、有机酸及氮素代谢关键酶活性的影响，同时确立了提取番茄中9种有机酸并利用高效液相色谱测定的方法，研究结果表明： 蒸馏水提取（水提）、80％乙醇溶液提取（v醇：v水=80：20）—旋转蒸发浓缩（醇提）、蒸馏水提取—冷冻干燥浓缩（水提冻干）三种提取方法下番茄果实中富马酸、丁二酸含量无显著性差异，草酸、酒石酸、苹果酸、草酰乙酸含量均以水提最高，而丙酮酸和柠檬酸以醇提含量最高。不同提取方法对小白菜叶片中草酸、酒石酸、富马酸含量无影响，其它几种有机酸（除草酰乙酸外）均以水提和水提冻干含量高于醇提，其中，水提法和水提冻干法提取丙酮酸、苹果酸、丁二酸的含量无显著差异，而柠檬酸含量以水提冻干法最高。综合考虑试验步骤和结果等各方面因素发现蒸馏水直接提取法既能有效保证有机酸的提取量，又能大大简化试验步骤。 在营养液总N含量不变的前提下，与全硝处理相比较，25％增铵营养（NH₄⁺：NO₃^-=25：75，简称增铵处理）能显著提高番茄生物量及鲜果重、可溶性糖含量、可滴定酸度及可溶性蛋白含量，但对番茄的糖／酸比、氨基酸及Vc含量影响不大。 与全硝处理相比较，增铵营养下番茄叶片内NO₃^--N含量显著降低，叶片与果实内NH₄⁺-N含量及果实的可溶性蛋白含量升高；增铵营养抑制了叶片和果实的硝酸还原酶（NR）活性，提高了及叶片谷氨酰胺合成酶（GS）活性，但对果实的谷氨酰胺合成酶（GS）活性影响不大。 增铵营养能够显著降低叶片、果实内苹果酸含量；果实内柠檬酸含量随增铵而显著增加，同时番茄叶片和果实内有机酸代谢关键酶PEPcase活性增强。果实内PEPcase活性与其有机酸含量呈显著正相关。 综上所述，25％增铵营养是一个比较合适的增铵强度，它能够促进番茄的氮素同更多还原

【Abstract】 The influences of enhanced ammonium nutrition on tomato growth, quality as well as the activity of nitrate reductase, glutamatesynthetas and organic acid content were studied. Also we founded a method that could extract 9 organic acids and determine together with one mobile phase by HPLC. The results were listed as follows.1. Organic acids were extracted from tomato fruit and Chinese cabbage leaves by distilled water directly (w), or by 80% ethanol (v: v=80:20) and then evaporation for concentration (E), or by distilled water for extraction and then frozen-evaporation concentration (WF). In terms of tomato fruits, the extracted amounts of fumarate and succinate were not influenced by extraction methods, while the amounts of oxalic acid, tartaric acid, malate and oxaloacetate extracted by W method were significantly higher than those extracted by the other two methods. E method could extract the highest amount of pyruvate and citrate. For Chinese cabbage leaves, no significant differences were found in oxalic acid, tartaric acid and fumarate extracted by the three extraction methods, whereas the amount of the other organic acids (except for oxaloacetate) extracted by W and WF method were significantly higher than those extracted by E method. There were no significant difference of pyruvate, malate, and succinate extracted by W and WF method while citrate amount extracted by WF was higher than that by W. Therefore, distilled water extraction (W) method was proposed to extract organic acids from tomato fruits when taking the extraction steps, working efficiency and extraction quality together into account.2. Twenty five percent of replacement of nitrate by ammonium led to a significant increase in fruit fresh weight. Also, the sugar content, the acidity and the protein content in fruits were higher in the treatment of enhanced ammonium nutrition than those in the treatment of pure nitrate. However the sugar/acid ratio, the amino acid content and the Vc content did not change a lot.3. The replacement of 25% nitrate with ammonium led to a significant increase in ammonium content in both leaves and fruits and soluble protein content in fruits, while更多还原