Effects Of Salicylic Acid(sa)on Growing Development And Quality In Flue-cured Tobacco Under Different Light And Temperature

ABSTRACT: The experiment studied the influence of salicylic acid (SA) on botanicalcharacteristics, photosynthetic characteristics, general nutrition and flavor matter during theprocess of growing development in flue-cured tobacco cultivar Zhongyan100under different lightand temperature condition. The study analyzed and evaluated the characteristics of a number ofindicators systemically association with the comprehensive index of flue-cured tobacco, the mainconclusions are as follows:1Effects of SA on growing development in flue-cured tobacco under differentlight and temperatureMorphological indexes of flue-cured tobacco existed differences under different lightconditions. The plant height, stem girth, leaf length and leaf width of flue-cured tobacco decreasedfirst and steadied later as the weakening of light after using SA. The plant height, stem girth, leaflength, leaf width, leaf area, leaf number and section spacing of flue-cured tobacco had a trend ofincreasing as the increasing of temperature after using SA. Morphological indexes of flue-curedtobacco changed under different environmental conditions and achieved to adapt the newenvironment under different light and temperature condition.2Effects of SA on mineral nutrition in flue-cured tobacco under different lightand temperatureMineral elements of flue-cured tobacco leaves impacted under different light conditions wererelatively significant. The content of macro-element was higher comparing with CK After treatingwith SA, and the trace elements content had a trend of increasing. Amount of all mineral elementsin the soil was gradually reduced after harvesting of tobacco leaves, and using SA could promotethe absorption of mineral elements by plants. By analyzing the distribution of mineral elements influe-cured tobacco, we could know the corresponding relationship between macro-element andtrace element content in flue-cured tobacco leaves and all mineral elements in the soil.The influence of different temperature condition in mineral elements of flue-cured tobaccoleaves was tremendous, SA could facilitate the absorption of flue-cured tobacco on K, Ca and Mgions, but the absorption of trace elements at high temperatures had a degree of inhibition. SA had apositive influence on the absorption of trace element under low and normal atmospheric temperature.3. Effects of SA on photosynthetic characteristics in flue-cured tobacco under different lightand temperature3.1The Impact on pigment contentUnder different light conditions and times during the development of flue-cured tobacco, thechlorophyll-a and chlorophyll-b content were increasing, and the numerical value of chlorophyll aand chlorophyll b content in60d after transplanting was the highest in each treatment. Interactionbetween light intensity and SA enabled leaf to capture more light energy and improved thephotosynthetic capacity in the late development times. Interaction between light intensity and SAreached a significance level in flue-cured tobacco at75d and90d after transplanting.Chlorophyll-a and chlorophyll-b content in flue-cured tobacco leaves gradually increased asthe temperature increased under different temperature treatments. But in the condition of hightemperature chlorophyll-a and chlorophyll-b decreased gradually after treating with SA, thecontent of phytoxanthin, beta-carotene, violaxanthin, and neoxanthin was consistent with changesof chlorophyll content in flue-cured tobacco maturity leaves as the temperature changes. SAmakes them increase.3.2The Impact on photo-synthesisUnder the different light levels, SA could increase leaf photosynthetic rate to a certain extentin flue-cured tobacco and improved the transpiration rate. Stoma conductance first raised and laterdecreased, what was different with rule of photosynthetic-transpiration rate. SA also helped toregulate the opening and closing of stoma in flue-cured tobacco leaves. Intercellular carbondioxide concentration also increased with increased shade in the flue-cured tobacco. SA couldimprove the photosynthetic rate through increasing intercellular carbon dioxide concentration.On maturity of flue-cured tobacco with different temperature when worked with5d or10d,photosynthetic rate of leaf decreased with temperature increasing， after15d， treating with SAonly increased photosynthetic rate of flue-cured tobacco leaves significant. Compared with theambient temperature, treating with low temperature and high temperature treatment could reducethe transpiration rate of flue-cured tobacco leaf. SA played a role of inhibition in transpiration rateof flue-cured tobacco leaf。So SA was not conducive of transpiration from leaves3.4Effects of SA on general nutrition in flue-cured tobacco under different light andtemperatureRoutine chemical components in flue-cured tobacco varied greatly under different lightingconditions. Total sugar, reducing sugar and starch content in flue-cured tobacco leaves reduced when the shade level increasing. The total sugar, reducing sugar and starch content decreasedwhen using SA in leaves. The influence of total nitrogen and nicotine content was not obvious,and the potassium content increased. The influence of light intensity and SA on total nitrogen,nicotine, total sugar, reducing sugar and starch had achieved a very significant level. Petroleumether extract of flue-cured tobacco decreased in shading, and had no difference between the SAtreatment and CK. The content of petroleum ether extract reduced under severe low light.Under different temperature conditions, total sugar and reducing sugar content decreasedoverall as temperature increasing, chlorine and total nitrogen content had an increasing trend,potassium occurs first raised and later decreased, nicotine appeared to first reduce and later rise.The total nitrogen, nicotine and potassium content decreased after using SA under low temperaturelevels, and other indicators increase. SA had no effect on total nitrogen under normal temperature,and the other indicators increase. The indicators on high temperature levels were on the rise. Thedifference of nicotine, potassium, total nitrogen and starch on each treatment reached significantlevels, the other indicators reached very significant level.3.5Effects of SA on aroma components in flue-cured tobacco under differentlight and temperatureDifferent lights with SA made content of l-phenylalanine increase. SA was benefit for thesynthesis of phenylalanine, hyacinthin and phenethyl alcohol. The effect on the dissolutions ofcarotene under different shading conditions was light. SA and shading treatments could improvethe content of neophytadiene and solanone. SA also could increase the content of bread ketones,guaiacol, aromatic camphor,2-6-nonane diene-aldehyde and crocein aldehyde.SA had a greater impact on flue-cured tobacco aroma under different conditions of temperature.SA made the Spicy, nut-flavored, and the Roses from phenethyl alcohol thin under the lowtemperature. SA made the content of l-phenylalanine degradation products decrease. SA madeSOAP fragrance and burnt odor thicken in flue-cure tobacco under the high temperature. SA madethe content of aroma substances of browning reaction increased under different temperaturecondition. SA had a different influence on browning reaction under different temperaturecondition in flue-cured tobacco. The dissolutions of carotene were the highest level under thecondition of high temperature, and SA made it less. Temperature made the content of solanonedrop, but SA could enhance the content of solanone. The content of neophytadiene increased. SAmade the total aroma of less content increase, but part of the content of aroma is decrease.