钾对烤烟碳代谢及其品质形成的影响

目的]研究不同施钾量对烤烟碳代谢和其品质形成的影响。方法]通过固定氮、磷水平（N 90 kg/hm2,P2O5 180 kg/hm2）,设置不同钾肥（K2O）施用量（0、90、180、270和360 kg/hm2）对烤烟碳代谢及其品质形成的影响。结果]施用适量钾肥提高烤烟中后期烟叶蔗糖转化酶和淀粉酶活性,促进烟叶由氮代谢向碳代谢的适时转换。在烤烟移栽后30和45 d,烟叶可溶性总糖、还原糖和淀粉含量随施钾量的增加而降低,而在烤烟移栽后60、75和90 d随施钾量的增加而增加。说明施用钾肥有利于降低烤烟生长前期的碳积累,而促进烤烟生长后期碳的积累代谢。结论]适宜的施钾量为270 kg K2O/hm2,在此条件下,烤烟产量最高和烤烟化学成分更趋于协调。

Effects of Potassium Nutrition on Carbon Metabolism and Quality of Flue-cured Tobacco

Objective]The research aimed to study the effects of potassium on carbon metabolism and quality of flue-cure tobacco.Method] In this experiment,different potassium(K2O) levels treatment(0,90,180,270 and 360 kg/hm2) was done under the same levels of nitrogen and phosphorus in field(N 90 kg/hm2,P2O5 180 kg/hm2).Result]The main results showed that the activities of invertase and amylase at the middle and later stage of tobacco growth increased with appropriate application of potassium,which was also beneficial for the transformation from nitrogen metabolism to carbon metabolism at suitable time.After 30 and 45 d of flue-cured tobacco transplant,the content of total soluble sugar,reducing sugar and starch in leaves decreased with the increase application of potassium at the early stage of tobacco,while increased with the increasing application of potassium levels at the middle and later stage after 60,75 and 90 d of flue-cured tobacco transplant,indicating the application of potassium would be better for carbon accumulation at the later stage but not at the early stage of tobacco.Conclusion] The appropriate quantity of adding potassium was 270 kg/hm2,at this experimental condition,the yield of flue-cured tobacco was highest and the quality was much more coordinate.