The Effects Of Applied N Amount And Topping On Bleeding Intensity And Endogenous Hormone In Cigar Wrapper

In 2005-2006,through field trial and pot experiment on the farm of Henan Agricultural University,relationship between dry matter accumulations in plants, bleeding intensity and change of endogenous hormone in root bleeding were studies. The effects of nitrogen fertilizer level on endogenous hormone and quality in the growth of cigar wrapper and the effects of topping on growth and development, endogenous hormone content in cigar wrapper were studies.The results were as follows:1 The accumulation of dry matter in various organs of cigar wrapper was the slow-quick-slow tendency.Changing trends of bleeding intensity,ZR and ABA contents in root bleeding were showed as a single apex curve from 38 d to 104d in cigar wrapper tobacco plants under fields.Bleeding intensity and ZR reached to the peak value at latter fast growing stage while for ABA at the rosette stage.The change trend of GA in root bleeding was showed a W type,when as an M for ABA.ZR/ABA has reflected a senescence advancement of cigar wrapper in the certain degree.The accumulation of dry matter in various organs was closely connected with bleeding intensity and endogenous hormone in root bleeding of cigar wrapper The correlation analysis showed that roots bleeding intensity,dry weight of roots,dry weight of stem and dry weight of leaves were related to ZR content positively and there correlation coefficients with ZR content were significant different.The roots bleeding intensity was related to ABA content negatively and its correlation coefficient with ABA content was significant.Endogenous hormone in roots bleeding of cigar wrapper tobacco is a kind of communication signals between root and shoot,they can infect the growth and development of above-ground.2 Root activity increased at the early stage and then declined during the growth of cigar wrapper under different nitrogen fertilizer levels.Reach the highest in 85 days after transplantion.Nitrogen fertilizer could enhance root activity during the stage of growth quickly.Lack of Nitrogen could cause premature senility.However, only proper nitrogen fertilizer level(N5 treat)could promote the growth of root.The correlation between root activity and endogenous hormones in root were not remarkable,these show increase of root activity couldn't enhance the ability of root synthesis endogenous hormones.The correlation analysis showed that ZR content, IAA content were related to ZR content in toot positively and there correlation coefficients with ABA content were significant different and significant,these inffected that endogenous hormones in root controlled the growth and development of cigar-wrapper by synergism.3 Application of N fertilizer could effectively improve N atrophic leave of tobacco leaves,increase aeras of leaves and content of chlorophyll The nitrogen nutrition promoted growth and development of leaves and controlled the senescence advancement of leaves through influence endogenous hormone content.But it wasn't the better whit more application of N fertilizes.Relation among N atrophic leave of tobacco leaves,growth and development,endogenous hormone contentin in leaves indicated that the change of N fertilizer effectived endogenous hormone contentin in leaves directry.The results indicated that only proper nitrogen fertilizer level(N5) could promote the increasing of leaves area.4 Under different nitrogen fertilizer levels,nicotine content increased with growth and development of cigar wrapper in field,total sugar and starch increased at the early stage and then declined。TN and K declined with growth and development of cigar wrapper in field,TN and K increased with the increase of nitrogen fertilizer.Nicotine content was the highest in N5 treat and the lowest in NO,it indicated that only proper nitrogen fertilizer level could enhance accumulate nicotine in leaves.Starch was the highest in N5 treat then K content was the highest in N10 treat.Stem content,leaf thickness,weight per area and weight per area increased with the increase of nitrogen fertilizer.Equilibrium moisture content and stretching resistance were higher in N5 treat and N10 treat.Physical property of N5 and N10 were better then NO treat and N15 treat.Based on special utility of cigar wrapper,the tobacco leaves had good quality under N5 treat and N10 treat and the usability of the leaves were better then N0 treat and N15 treat.5 The study suggested that topping promoted root system's second growth compared with before topping then enhanced the ability of root synthesis endogenous hormones,with bleeding intensity of root increased,and correspondingly increased endogenous hormone(ZR,IAA,GA and ABA)which transports along the tobacco stem xylem to aerial parts.Topping also changed endogenous hormone content of leaves in a certain degree.Nitrogen is one of main nutritive element that is needed by tobacco in growing.It controls the growth and development of cigar wrapper trough affects the root activity and endogenous hormone contents.Compared with before topping,the change tendency of root activity,endogenous hormone content in tobacco was obvious with the increase of nitrogen fertilizer.