Interaction Among Potassium,Calcium And Magnesium And The Effect On Carbon Metabolism And Nirtrogen Metabolism In Flue-cured Tobacco

Flue-cure tobacco is one of the important economic plants in FuJian province. The high content of potassium and proper content of calcium and magnesium in tobacco leaf have good effect on the quality of Flue-cure tobacco. The status of carbon metabolism and the harmony with nitrogen metabolism in Flue-cure tobacco correlate to the content of carbohydrate and nitrogenous compounds in Flue-cure tobacco leaf, therefore influencing greatly the production and quality of tobacco leaf. This experiment studies the rule of absorption K, Ca and Mg by Flue-cure tobacco K326 and the interaction among them by hydroponics experiment under 5 treatments(control(CK): K I Ca : Mg=234 : 200 : 60 (3.9 : 3.3 : l);treatmentl: K : Ca : Mg =351 : 100 : 12 (29.3 : 8.3 : 1); treatment K : Ca : Mg =351 : 100 : 60 (5.9 : 1.6 : 1); treament3 K : Ca : Mg=468 : 240 : 12 (39 I 20 : 1); treatment4 K : Ca : Mg=468 : 240 : 60 (7.8 : 4 : 1)), and the effect on carbon metabolism and nitrogen metabolism in Flue-cure tobacco as well. The study result indicates that with the level increasing of K, Ca and Mg, the absorption by Flue-cure tobacco also increase; with the growing of Flue-cure tobacco, the content of K, Ca and Mg in leaf decreases; There is a synergistic effect among K, Ca and Mg by treatment 4, which meets the high quality of Flue-cure tobacco owing to the content of K, Ca and Mg. Meanwhile, high activity of In V SPS and SS in leaves at the prophase of growth by treatment 4, and low InV activity at anaphase while keeping higher SS, which makes the carbon catabolism bloom at the prophase growth and tobacco grow fast ahead of time. Thecarbon accumulation metabolism increases and pool more carbohydrate atthe anaphase, and there are higher amount of total soluble sugar, reducing sugar and starch. As to nitrogen metabolism, NR and GS activity are higher at blooming phase, lower at anaphase of growth, which make the Flue-cure tobacco have stronger nitrogen metabolism at prophase and help build tobacco body, and turn to carbon metabolism at anaphase, thus make the amount of total nitrogen and protein drop, nicotine and amino increase appropriately.