The Effects Of Nitrogen Forms On Tobacco Metabolism,Yield And Quality Under Low Temperature

Ammonium and nitrate are two forms of nitrogen which are absorbed in the development of flue-cured tobacco. We studied the effects of two forms of nitrogen on tobacco’s physiological metabolism under low temperature, which are very important for guiding the production of flue-cured tobacco. We conducted cultured solutions and field trials in Fujian Tobacco Institute of Agricultural Sciences Huanxi experimental base with K326 and CB-1 as tested Tobacco Varieties from 2014 to 2015. We conducted comparative analysis from agronomic traits, carbon and nitrogen metabolism, chemical composition, tobacco smoking and yield monitor, etc. The main conclusion of this study are:1 Results from water culture1.1 The affect of different nitrogen forms and ratio on tobacco photosynthetic characteristics. It was found that in the flue-cured tobacco’s seedling stage; Chla, Chlb, Chl, Chlx.c and Chla / Chlb content fertilizing with nitrate are higher than fertilizing with ammonium despite different nitrogen forms and ratio. Nitrate is more conducive to the accumulation of chlorophyll content. The chlorophyll content between the two tobacco cultivars was not significant. The photosynthetic parameters of Tr, Gs, Pn were the highest under application of only nitrate, and are the lowest under application of only ammonium. It was showed that nitrate process was more conducive to improve the efficiency of light capture and conversion of blade, and could delay leaf’s senescence. Different nitrogen forms and ratio have little impact on fluorescence parameters and the two tobacco cultivars had little difference.1.2 The impact on leaf area and dry matter’s accumulation of flue cured tobacco among treatments with different nitrogen forms and ratio. The study found that the dry matter’s accumulation of the whole plant and leaf area of tobacco are the highest under application of only nitrate nitrogen, applying only ammonium nitrogen was the lowest. It showed that the only application of nitrate was more conducive to the growth of tobacco, on the other hand ammonia nitrogen inhibited the nonnal growth and development of tobacco’s seedlings to some extent. Effects of different nitrogen forms and ratio on the two tobacco’s leaf area and dry matter accumulation were not obvious under low temperatures. Ammonium inhibited K’s accumulation of roots, stems, leaves in some extent. Different nitrogen forms and proportion have various effects on nitrogen, phosphorus content of tobacco.1.3 The impact of different nitrogen forms and ratio on flue cured tobacco physiological metabolism of carbon, nitrogen, etc.The GS, GOGAT activity of tobacco were the highest under ammonium process. To a certain extent, it eased the damage from poisoning of salt to seedlings. The GS’s, GOGAT activity of CB-1 was greater than K326 and more adapted to low temperature and light. The tobacco seedlings of high nitrate had lower synthetic sugar, reducing sugar, soluble sugar, fructose and sucrose; while the soluble protein content was higher. It showed nitrate was more conducive to tobacco carbon metabolism and the volume of carbohydrate tobacco’s CB-1 was greater than K326. The root’s respiration rate was the highest under application of only nitrate nitrogen and ammonium nitrogen was the lowest and mean application of only nitrate was more conducive to root’s growth; the root’s respiration rate of CB-1 was higher than K326.1.4 The impact of different nitrogen forms and ratio in tobacco’s active oxygen metabolism. The SOD, POD, MDA content were the lowest under application of only nitrate nitrogen in the two tobacco cultivars, tobacco’s membrane damage extent under nitrate treatment were lesser than the other forms of nitrogen, and nitrate treatment was more conducive to the growth of tobacco seedlings. The CAT content of flue-cured tobacco varied when suffered stress under different degree. The MDA content of K326 was significantly higher than the CB-1 under only application of ammonium-treated. The SOD, POD content of K326 were significantly higher than CB-1 under application of only nitrate and 50% ammonium+50%nitrate processing. Since CB-1 was more adapted to low temperature processing than K326, CB-1 had strong antioxidant live ability and less susceptible to oxidative damage.1.5 The research of tobacco proteomics under different nitrogen forms and ratio. We studied the expression of differential protein in flue-cured tobacco’s seedling stage with different nitrogen forms and ratio using 2-DE and successfully identified 19 protein spots by mass spectrometry analysis, among which we obtained 17 proteins. Including photosynthesis, energy metabolism, stress and aroma associated related protein, which had 10 photosynthesis-related proteins. It was showed that different nitrogen forms and ratio mainly affected the growth of tobacco through photosynthesis under low temperatures. The K326 expression of differentially expressed protein was substantially higher than CB-1, which may be due to the the compensation and super compensation effect.2 Field test results2.1 The effect of different nitrogen fertilizer on Tobacco biomass and photosynthetic characteristics. We found that tobacco’s dry matter accumulation was gradually increasing with extending of growth period, while different nitrogen fertilizer had little effect on dry matter accumulation of flue-cured tobacco, The growth rate of KNO3 and NH4NO3 is higher than NH4HCO3 and (NH4)2SO4, and the treatment of only application of nitrate or higher nitrate proportion helped to improve the growth rate of tobacco to a certain extent. The impact of different nitrogen fertilizer on net photosynthetic rate was not significant among the tobaccos. Fluorescence parameters indicators of NH4NO3 was the highest substantially, and the NH4NO3 process of Fv、 Fm were significantly higher than NH4HCO3.2.2 The effect of different nitrogen fertilizer on tobacco sensory evaluation and economic characteristics. Compared to other treatments, tobacco treated with (NH4)2SO4, lacked of aroma, and had lowest score which Fen style weakened, steering Luzhou, and sweetness changed into clear focus; decreased the finest of tobacco, the tobacco’s medium, yield, value and average price. KNO3 promoted the yield and quality of flue-cured tobacco to some extent, Fen style was significant and had sufficient aroma.Results from water culture and field experimental showed that we should increase the proportion of nitrate fertilizer in the early stage of growth, and excessive ammonium nitrogen inhibited the seedling growth to some extent.