为探讨氮、磷、钾肥对烤烟碳氮代谢关键酶活性及其经济效益影响,采用田间小区试验,测定了缺氮、缺磷、缺钾和氮磷钾正常(CK)处理烤烟不同生育时期碳氮代谢关键酶即硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、蔗糖磷酸合成酶(SPS))、蔗糖合成酶(SS)和转化酶(INV)的活性变化.结果表明:在烟叶的氮代谢过程中,NR活性主要在烟叶生长发育前期起作用,与CK相比,氮、磷、钾素缺乏分别使烟叶NR活性下降35.9％,13.4％,19.5％,但移栽后85 d无差异显著性；在碳代谢过程中,SPS,SS和INV活性主要在烟叶生育中期起作用,缺氮能显著降低碳代谢关键酶活性,而缺磷、钾素则表现不明显,很可能与试验田磷钾含量较高有关.缺氮处理对烟叶的产量、产值影响最大,与CK处理相比,分别降低了19.7％,13.2％,缺磷、钾素处理与CK差异不显著.因此,烤烟为达到优质高产,首先要确保氮肥供应充足,同时要适当控制磷钾肥用量.%The purpose of the paper was to study the effect of N, P, K fertilizer on the activeness of key enzymes involved in C and N metabolism during leaf development and the economic benefit of flue-cured tobacco. Four different treatments (i. e. nitrogen, phosphorus, potassium deficiency and CK) were designed in a field experiment to study the enzyme activeness of nitrate reductase ( NR ) , Glutamina synthetase ( GS ) , sucrose phosphate syhthase (SPS) , sucrose synthase ( SS) and invertase (Inv). The results showed that NR was majored at the early growth stage of flue-cured tobacco. Compared with CK,the NR activity of N,P and K lack treatments decreased by 35. 9% , 13.4% and 19. 5% , respectively, but no significant difference was detected after 85 d of transplanting. In the process of carbon metabolism,the key enzymes SPS.SS and INV played a major role at the middle growth stage. N deficiency could decrease significantly the activeness of key enzyme, while P and K deficiencies had no obvious affect , probably because of the higher levels of phosphorus and potassium in the experiment plots. The effect of N lack on leaf yield and output value of flue-cured tobacco was the greatest compared to CK, decreased by 19. 7% and 13. 2% respectively, and the lack of P and K elements had no significant difference with CK. This indicated that N fertilizer should be sufficient, and P and K elements should be controlled properly in order to obtain flue-cured tobacco with high yield and good quality.
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