为了研究基于SPAD值精准施氮模式对烤烟生理期碳代谢的影响。以K326为试验材料,设置基于SPAD值的烤烟实时氮肥追施的施氮方式(SPAD阈值为43)和传统农家施氮方式两个处理,以两个处理烟株的第4叶、第10叶和第18叶作为下、中、上3个部叶的代表叶片来研究碳代谢碳水化合物含量及酶的活性。随着烟龄的增加,上、中、下部叶总糖、还原糖、蔗糖和淀粉的含量均表现出增加的趋势,而中、上部叶的蔗糖和淀粉含量在后期又有所回落,与农户惯用施肥模式相比,基于SPAD值施氮模式下的上、中、下部叶的还原糖、总糖、蔗糖磷酸合成酶和淀粉酶的含量均较高,而淀粉和淀粉磷酸化酶含量则相对较低,蔗糖和蔗糖转化酶在烟株生长前期较高,但后期低于传统农家施氮方式。说明基于SPAD施氮模式迎合了烟株生理期碳代谢的变化规律,有利于烟株碳代谢的进行。 In order to study the effect of precise nitrogen application based on SPAD value on carbon metabolism in flue-cured tobacco during physiological period. Using K326 as the experimental material, two methods of nitrogen application (SPAD threshold of 43) and traditional farmland N application were set up based on the SPAD value, And the 18th leaf as the representative leaves of the lower, middle and upper three leaves to study carbohydrate metabolism and enzyme activity. With the increase of tobacco age, the content of total sugar, reducing sugar, sucrose and starch in upper, middle and lower parts showed an increasing tendency, while the content of sucrose and starch in middle and upper leaves also declined later, The contents of reducing sugar, total sugar, sucrose phosphate synthetase and amylase in upper, middle and lower leaves under SP mode were higher, while those of starch and starch phosphorylase were relatively Lower, sucrose and sucrose invertase were higher in tobacco plants at the early growth stage, but lower at the later stage than the traditional farmland nitrogen application. The results showed that the pattern of carbon metabolism in tobacco plants catered to the change of carbon metabolism during the physiological period of tobacco plants based on the SPAD nitrogen application pattern, which is in favor of the carbon metabolism of tobacco plants.