| A water-culture experiment and experiments in pot was conducted to study the change of potassium content, nicotine content and endogenous hormones. The relationship of endogenous hormones and potassium content, nicotine content after topping were studied. The changes of various physiological indicators and the main chemical components were tested by different ways such as IAA,GA3,ABA,ZR,Put,PAO,IAAO,LOX and ATPase.The relationship of exogenous plant growth regulators,potassium and nicotine were studiedalso. Test results are as followed:1. Effects of different exogenous substances on the content of endogenous hormones in the upper leaves and roots of flue-cured tobacco.The endogenous hormones have been obvious changed by topping, the IAA content and GA3 content reduced and the ABA content increased, ZR content increased then reduced. The trend of this change is consistent both in the leaves and in roots. The contents of IAA and GA3 decreased by topping and the rate of decreasion increased after spraying Put and JA, the better effect is Put; After spraying Put and JA, there has an increasion in ABA content, and it has a greater impact after spraying JA; The ZR content has also increased in some way, but the rate of the increasation was little. The trends of these endogenous hormones in the roots were similar with the trends in the leaves.After topping, endogenous putrescine content increased rapidly, after spraying IAA and GA3 the endogenous putrescine content in leaves decreased, and the more obvious effection is IAA. The endogenous putrescine content in leaves was increased by spraying Put. Spraying ABA, JA and 6-BA had little change of Put content compared to the treatment of topping. There has a slight difference of the Put content during different treatments. The Put content in roots after spraying ABA,JA,Put and 6-BA is more than the treatment of topping. The effection of IAA treatment is better than the GA3 treatment. The Put content in roots is higher than spraying ABA, JA, Put and 6-BA , of which the Put treatment is the highest.2. Effects of different exogenous substances on enzyme activity in the upper leaves and roots of flue-cured tobacco.The enzyme activity in the upper leaves and roots of flue-cured tobacco changed after topping. Different exogenous plant growth regulators have different effect on enzyme activity.The activity of LOX raised rapidly after topping, and it increased after spraying JA and Put. The treatment of JA increased obviously. The activity of LOX decreased after spraying IAA and GA3,and it wasn't obvious of other treatment. The enzyme activity of LOX in roots was similar with which in leaves. The enzyme activity of IAAO increased after topping but the activity decreased after spraying exogenous plant growth regulators. The decrease rate was little after spraying JA and Put but there was a larger decrease by spraying IAA and GA3. The enzyme activity of IAAO performanced for the trend of reduced firstly and then increased with topping. The enzyme activity of the treatment by spraying IAA,GA3,ABA and 6-BA reduced more than the treatment of topping, of which the treatment of JA and Put reduced little; The PAO activity of the treatment without topping raised continually, but the rate was limit. The enzyme activity of PAO performanced for the trend of increased firstly and then reduced with topping. The PAO activity of spraying Put treatment was higher than the treatment of topping. The PAO activity of spraying IAA,GA3 treatment was significantly lower than topping treatment in any period and the PAO activity had little change of other treatments. The PAO activity in roots was similar with in the upper leaves, and the PAO activity was lower. The enzyme activity of ATP sharply increased, and reached the peak at the 7d after topping. The enzyme activity of IAA treatment was the highest at the 21d after topping, and the GA3 treatment followed. The ATPase activity of JA treatment,Put treatment,ABA treatment and 6-BA treatment was lower than the treatment of topping in the upper leaves, of which, JA and Put treatment has a larger decrease. The ATPase activity in roots increased firstly and then reduced, and at the 14d it reached the peak. The activity reached the peak after topping of IAA treatment, and the GA3 treatment followed. The enzyme activity of JA treatment,Put treatment and ABA treatment was lower than the topping treatment.3. Effects of different exogenous substances on potassium and nicotine in the upper leaves and roots of flue-cured tobacco.The potassium in tobacco leaves increased of the treatment without topping, and in the other treatment the potassium decreased after topping. The treatment of spraying IAA,GA3 can improve the content of potassium, but spraying ABA,JA and Put can decrease the content of potassium, of which, the Put treatment was the most obviously one. With the prolong of the life, the potassium content increased firstly and then decreased. The potassium content of the treatment without topping increased slowly.The nicotine content increased in the treatment without topping, but the growth rate was limited. The nicotine content increased obviously after topping, and in the treatment of spraying JA and Put the nicotine content increased rapidly, but the change of ABA treatment was not obvious. The nicotine content in the treatment of IAA,GA3 and 6-BA decreased,and the decrease rate of 6-BA treatment was little. In the roots, the nicotine content increased rapidly after topping, the nicotine content of the treatment without topping increased slowly.Spraying ABA,JA and Put can increase the nicotine content, and Spraying IAA and GA3 can decrease the nicotine content.4. The relation among potassium,nicotine and endogenous hormones after toppingIn the leaves of the tobacco without topping, The endogenous IAA and GA3 had negative correlation with potassium, but it did not reach a significant level. ABA had positive correlation with potassium; Among the different treatments after topping, IAA and GA3 had positive correlation with potassium content, and ABA had negative correlation with potassium; In the treatments without topping, the Put content had positive correlation with potassium content, and the other treatments had negative correlation with potassium, of which, the treatment of spraying IAA and GA3 did not reach a significant level.Among the different treatments, IAA and GA3 had negative correlation with nicotine. ABA had positive correlation with nicotine content. ZR had negative correlation with nicotine content of the treatment without topping, but it did not reach a significant level. Among the different treatments, Put had positive correlation with nicotine content. The potassium content had negative correlation with nicotine content after topping. |
PDF Full Text Request