Regulating Effect Of Nicotine Content Of Flue-Cured Tobacco With Exogenous Regulators

This experiment was conducted with the variety of K326. Different exogenous regulators of BF1,ABZ and CC were sprayed on the flue-cured tobacco leaves under the level of 20 leaves remained after topping with different combinatorial mode to study the effect of these exogenous regulators on the nicotine content and other chemical components, and analyzed the position distribution of nicotine content and the chemical components coincided with nicotine content, and analyzed the mechanism of regulating nicotine content based on the effect of exogenous on nicontine-stream and physiological respond of the tobacco. The main conclusions were as follow:1. Study on correlation of main chemical components in leaves of flue-cured tobacco and its position distribution. The results showed that: coincided with the nicotine content of≤1.5%, the value of sugar/nicotine, nitrogen/nicotine and K₂O/nicotine were respectively≥12,≥1.2,≥1.0; coincided with the nicotine content of 1.5%～2.0%, the value of sugar/nicotine, nitrogen/nicotine and K₂O/nicotine were respectively 12.2～15.4, 1.1～1.4, 0.7～1.0; coincided with the nicotine content of 2.0%～3.0%, the value of sugar/nicotine, nitrogen/nicotine and K₂O/nicotine were respectively 7.4～12.2, 0.7～1.1, 0.3～0.7; coincided with the nicotine content of 3.0%～3.5%, the value of sugar/nicotine, nitrogen/nicotine and K₂O/nicotine were respectively 5.9～7.4, 0.6～0.7, 0.2～0.3; coincided with the nicotine content of≥3.5%, the value of sugar/nicotine, nitrogen/nicotine and K₂O/nicotine were respectively≤5.9,≤0.6,≤0.2. They respectively distributed at the 1-5th leaves, 1-5th leaves, 6-10th leaves, 11-15th leaves and 16-20th leaves under the condition of 20 leaves remained with topping. The leaves position distribution of coincided chemical quality characters combination would not be changed by changing the time of topping. While changing the amount of leaves remained with topping would result in the changing of the distribution; When treated with exogenous regulators, the leaves position distribution of coincided chemical quality characters combination were not be changed, the treatment of BF₁+CC improved the applicability of lower tobacco leaves of the 1-10th leaf position, and the treatment of ABZ+CC improved the applicability of upper tobacco leaves. The correlative character of the applicable chemical components above can be the important theoretical foundation.2. Study on the effect of different exogenous regulators on chemical quality in different position of the tobacco leaves. Results showed that: with the treatment of BF₁, the nicotine content of the 1-15th leaves were increased significantly; with the treatment of ABZ and CC, the nicotine content of middle and upper leaves were reduced significantly; with the treatment of BF₁+CC, the nicotine and K₂O content of lower leaves were improved significantly, and the soluble sugar content of total leaf position were all in the high quality level; and with treatment of ABZ+CC, the nicotine content of upper leaves were reduced significantly, the soluble sugar content of the 11-15th leaves were on the high side. The analysis of the ratio of chemical components content showed that, the value of N/nicotine, sugar/nicotine and K20/nicotine were more feasible with the treatments ofABZ+CC,BF1+CC than the other treatments.3. Study on the kinetic of the space distribution of the nicotine content and the flow of nicotine in the plant of tobacco. The othemess of the nicotine inputted to the leaves from the roots under different exogenous regulators were determined on the qualitative point. Results showed that, when the exogenous were used soley, the treatment of ABZ reduced the nicotine were regulated to "resort" in the shoot in the 1-10th leaf position, and "resort" in the shoot and nervure in the 11-20th leaf position. The treatment BF₁ improved the nicotine content of total leaf position with regulating the flow of nicotine transported from the root. With the treatment of CC, the nicotine content of 1-10th leaf position was improved with regulating the flow of nicotine transported from the root, the nicotine content of 16-20th leaf position was reduced with regulating the nicotine "resort" in the nervure.; when the the exogenous were used combinatorially, with regulating the flow of nicotine, the treatment BF₁+CC improved the nicotine content of the 1-10th leaf position, and the treatment ABZ+CC reduced the nicotine content of 11-20th leaf position4. Study on the effect of exogenous regulators on nicotine content based on the technical concept of reducing the nicotine content of specific leaf area and weight. Results indicated that, the nicotine content of specific leaf area in the middle and upper leaves was lowest with the treatment of ABZ. In the 11-15th leaves, the nicotine content of specific leaf weight were all significantly higher than the comparison with the treatment of BF1, CC and ABZ+CC, and there was no significantly difference between the treatment ofABZ, BF1+CC and comparison; In the 16-20th leaves, with the treatments except BF1, the there was no markedly difference to comparison of the nicotine content of specific leaf weight.5. The correlation analysis showed that, there was positive correlation between nicotine content of upper tobacco leaves and root activity, bleeding intensity, while there was negative correlation between nicotine content of upper tobacco leaves and Chlorophyll content, net photo synthesis rate, stomatal conductance, intercellur CO₂, transpiration rate. The analysis of the rate of first class leaves indicated that CC＞BF1＞BF1+CC＞ABZ+CC＞CK＞ABZ, and the rate of first and middle class leaves BF1+CC＞CC＞BF1＞CK＞ABZ+CC＞ABZ. The analysis above showed that, the treatment of ABZ made against improving the the rate of first and middle class tobacco leaves, although it was the best to reducing the nicotine content of upper leaves, because the chemical components were all mensurated with choosing the middle-class tobacco leaves.6. The exogenous regulators compages BF₁+CC was identified that could balance the nicotine content of different leaf position and improve the ftrst and middle class rate. The analysis of chemical quality,nicotine-stream and nicotine content of specific leaf area of the middle rate leaves showed that, the treatment ABZ+CC was the best to improve the quality of tobacco leaves. But in production, the first and middle class rate of leaves must be insured chiefly. And the experiment results showed that, the first and middle class rate of leaves under the treatment ABZ+CC was less than the comparison treatment, while the treatment BF₁+CC could improve the applicability of the lower leaves with increasing the nicotine content significantly, the first and middle class rate of leaves were higher than the other treatment significantly also, though it could not reduce the nicotine content of upper leaves significantly. As a conclusion, the treatment BF1+CC was the best to improve the quality of tobacco leaves.