Research Of Difference Nitrogen Metabolism Between Flue-cured Tobacco Varieties And Regulation Technology In The Mature Period

Study on the different flue-cured tobacco leaf N metabolism characteristics and differences in the mature period,using the ammonia gas collecting device to determine the relative amount of ammonia volatilization of tobacco leaf,and probes into the amount of ammonia volatilization and N metabolism related indicators.And by extracting apoplast and the methods of determination of N metabolism related enzymes,the N nutrition level and different concentration of glutamine synthetase(GS)inhibitors(Glufosinate)ammonium N in flue-cured tobacco maturity inefficiency and indicators related to N efficient varieties of nitrogen metabolism.The results show that the:1.Tobacco amount of ammonia volatilization first increased and then a downward trend,maximum in leaf age 60d,Zhongyan90,K326 and NC89,respectively,16.39±1.08 ?g·m-2·h-1,9.92±1.04 ?g·m-2·h-1,4.56±0.63 ?g·m-2·h-1,respectively,3.87,2.41 and 2.56 times the of leaf age 40d ammonia volatilization,the significant difference between the varieties.The amount of ammonia volatilization and GS activity was a significant negative correlation,with the GDH activity,apoplastic NH4+ concentration and pH,ammonia compensation point was a very significant positive related,with the content of soluble protein and NR activity was significantly negative related,with the leaves NH4+ concentration was quadratic curve,and correlation extremely significant with,and are subject to total N degradation of indirect control.During the tobacco senescence,varieties of low N use efficiency,aging fast,N absorption and assimilation capacity is weak,transfer capacity,ammonia volatilization amount is big.varieties of high N use efficiency,aging slow,N absorption and assimilation capacity is strong,transfer capacity,ammonia volatilization amount is small.There are differences in different N efficient varieties on N reassimilation and transfer ability,and it is associated with tobacco leaf N metabolism characteristics and speed of aging.Tobacco leaves volatilization ammonia by apoplast,increase the transfer of NH4+,reduced the accumulation of ammonia pollution,is an important method of plant N metabolic regulation.2,N inefficient compared with N efficient varieties under the same processing,large amount of soluble protein and total N degradation,low GS activity decline,GDH activity is high,the low NR activity,high ammonia compensation point,high yield,production value and the proportion of superior tobacco,significant difference between the varieties.With the increase of N application rate,increasing N metabolism,each index all have the varying degree rise,N efficient varieties quantity of N nutrient degradation percentage is high,the GS activity decline and less affected by the amount of N,GDH activity and ammonia volatilization potential growth,significant difference compared with N efficient varieties.N application rate of N efficient varieties NC89 in tobacco leaf during more than 45.00 kg hm 2 cause of N nutrients accumulation is large,slow degradation,leaf NH4 concentration decreased,NR and GS activity is high,the low GDH activity,ammonia volatilization potential decreased,the yield and output value has fallen dramatically.N efficient varieties in N application rate and Yuyan 10 is 60.00 kg·hm-2 at blade NH4+ concentration,GDH activity and ammonia volatilization,potential output and output fell,but with the n application rate of 45.00 kg·hm-2 than when a drop is small,and total N degradation percentage is very high.3,GS inhibitor can effectively inhibit tobacco leaf GS activity during aging,decreased N assimilation ability,promote the degradation of N nutrition,and inducing GDH activity increases and NR activity decreased,leaf accumulation of NH4+,increasing the ammonia volatilization potential,and with the increase of GS inhibitor concentration,the inhibiting effect is more obvious.Compared N efficient varieties and N efficient varieties,the aging speed,blade less accumulation of NH4+,potential ammonia volatilization,significant difference between the varieties.GS inhibitor can accelerate leaf senescence,promote N degradation and transfer again.4,The results revealed that leaf size increase ammonia volatilization,make a lot of NH4+ through volatilization of plants apoplast,reduce the accumulation of ammonia pollution,increases the transfer of NH4+,is an important way of plant regulation of N metabolism.Shows different N efficiency of N metabolism in tobacco genotypes and assimilation and transfer ability difference.Variety of small amount of N and low utilization efficiency of N assimilation and the transfer is big,the N of applicability is wide and adjustment ability is strong,while N efficient varieties and large amount of assimilation,transfer is small,the N of the applicable scope is small,adjust ability is weak.Varieties of tobacco leaf ageing N metabolism associated with tobacco leaf senescence speed,the GS for ammonium assimilation ability and control ability of ammonium transfer apoplastic plays a leading role.