| The experiments were carried out on the experiment farm ,greenhouse,netroom of USTC and GuQuan town, Xuancheng city in AnHui from year 2001 to year 2002, by using the principle and methods of tobacco chemistry, phtology, biochemistry, tobacco cultivation, tobacco biochemistry, Flue-cured tobacco nourishment, to study the mechnism of accumulation and influence factors of nicotine by the pot and farm experiments.The main results of the study as follows:1. Effects of variable pH values(4.50,5.50,6.50,7.50,8.50) on root absorbing area of Flue-cured tobacco and nicotine content ,total nitro gen,protein and polyphenolic compounds were studied. The results indicated as pH values in the range from 4.50 to 7.50, the volume and dry weight of root increased as pH values increased, as well as AAAR(activate absorbing area),TAAR(total absorbing area). The relationship of nicotine and total nitrogen accumulation with pH values was parabola,the functions were Y=-61.429X2+391.17X-162.8 (F=l 8.45"), Y=-24.3X2+154.88X+52.7 (F=14.40**) respectively. When pH value got rise to 7.50, the accumulation of nicotine and total nitrogen attained the highest . Protein content descreased slowly and the values of shmuk increased as pH values in the range from 5.50 to 7.50, polyphenolic compounds (chlorogenicacid and rutim) got down. Root system configuration changed for shortening and the side roots descreased. AAAR,TAAR were lest, but nicotine, total nitrogen, as well as protein content were higher when pH value reach 8.50.2. Effects of spraying Mg(1.50%)combined B(0.30%),Mg(1.50%), B(0.30%), Mo(0.10%), Ca(0.01%) on nicotine content and quality of flue-cured tobacco leaves at regiment and prosperous period showed that each middle and trace elements can descend nicotine content .After spraying Mo ,nicotine content was lowest ,the influence of spraying B combined Mg on nicotine content decending better than singly sprayed B or Mg .The effect of spraying middle and trace elements on nicotine content had an order :CK>Ca>B>Mg>B+Mg>Mo . Except B and Mg, other elements on nicotine content were significant difference . Activity of pofyphenolic oxide after each element treatment was that :Ca>B+Mg>Mo>B>Mg>CK , polyphenolic compounds was : CK > Mg >Mo>B+Mg>B>Ca . Middle and trace elements descreased the protein conten. Reduced sugar ,total sugar content in an order : Mo>B>Mg>Ca>Mo>B+Mg>CK .The experiments also indicated that nicotine content was descreased by spraying middle and trace elements ,in contrast to shmuk values .3. Effects of different planting density, nitrogen levels and left leaves on nicotine content ,total nitrogen ,total sugar ,polyphenolic compounds .values of output and yield of Flue-cured tobacco by using cross design and statistical analysis . The results showed that, along with planting density increased ,nicotine content in the upper leaves descreased and got extreme significant difference, in contrast to the values of output and yield. The effects of different nitrogen levels on nicotine content in the upper leaves was significant defference ,and was insignificant for middle leaves ,but the effect on the lower leaves was extreme significant .In general , as applications of nitrogen increased ,nicotine content got rise . Effects of left leaves on nicotine content in the upper leaves were insignificant, but for the middle leaves were significant and extreme significant for the lower leaves . Topping may help to increase nicotine content ,ten days after topping nicotine content got rise to twice, after that every ten days (not including roasted ), the velocity of nicotine content increasing was slower gradually . The relationship between nicotine , total nitrogen content in the upper leaves and the days after topping can be expressed by using Y=kX" .As days after topping increased, total nitrogen content had a trend of descreasing .4. Effects of different plant growth substanc... |
PDF Full Text Request