氮、磷、钾用量和配比对温室黄瓜叶片相关代谢酶活性的影响

以氮、磷、钾配比1∶0.5∶1.2为对照,研究了不同氮、磷、钾用量和配比对温室无土栽培黄瓜叶片部分代谢关键酶活性的影响。结果表明,增加氮素的用量和配比,黄瓜株高、茎粗、植株干重均先升后降,硝酸还原酶活性显著增强,蔗糖合成酶、蔗糖磷酸合成酶和Mg2+、Ca2+-ATPase活性先升后降;增加磷素用量和配比,株高、茎粗、植株干重随之增大,硝酸还原酶活性先升后降,但蔗糖合成酶、蔗糖磷酸合成酶及Mg2+、Ca2+-ATPase活性显著升高;同时增加氮、磷用量和配比可显著提高硝酸还原酶、蔗糖磷酸合成酶以及Mg2+、Ca2+-ATPase的活性,但显著降低蔗糖合成酶活性;增加钾素用量和配比对黄瓜株高、茎粗和植株干重影响较小,适当增钾显著或极显著提高硝酸还原酶、蔗糖合成酶和Ca2+-ATPase的活性,Mg2+-ATPase活性升高不明显,进一步增加钾素用量和比例,上述酶活性均显著降低;增钾对蔗糖磷酸合成酶活性的影响不显著。

Effects of NPK rates and ratios on activities of metabolism enzymes in leaves of cucumber in greenhouse

Using ratio of N∶P₂O₅∶K₂O=1∶0.5∶1.2 as control,effects of different NPK rates and ratios on activities of metabolism enzymes in leaves of cucumber (Curcumas sativa L.) soilless-cultured in greenhouse were studied.The (results) showed that an increasing the rate and ratio of nitrogen caused plant height,stem diameter,and seedling dry weight,first to increase and then to fall;NR(nitrate reductase)activity in leaf rose significantly while SS(sucrose synthetase),SPS(sucrose phosphate synthetase)and Mg²⁺,(Ca²⁺ ATPase) activities first increased and then fell.When more phosphorus was applied,plant height,stem diameter and plant dry weight increased correspondingly,so did the(activities) of SS, SPS and Mg²⁺,Ca²⁺-ATPase,but the NR activity rose then fell.The NR,SPS and Mg²⁺、(Ca²⁺-ATPase) activities at higher nitrogen and phosphorus ratios were remarkably higher than those in CK,however SS activity(decreased) significantly at the same time.Increasing the rate and ratio of potassium had fewer influences on plant height,stem diameter,dry weight and leaf SPS activity;while NR,SS and Ca²⁺-ATPase activities remarkably increased when potassium rate was 2 times the control,Mg²⁺-ATPase activity rosed slightly;However,activities of enzymes mentioned above decreased when the rate and ratio of potassium increased to 4 times the control.