Quality Conditions Of The Upper Leaves And Effects Of Altitude On Flue-cured Tobacco Quality In Biiie Prefecture

The upper leaves of Bijie different tobacco producing counties in a widerange were collected to evaluate the quality characteristics of Bijie area of upperleaves and explore the key ecological factors affect tobacco quality, through thedetection of conventional chemical composition and neutral aroma constituents. Theexperimental conclusions were as follows. Through the filed experiments in2010and2011, this paper discussed the effects of ecological conditions on the botany shapes,the growth periods, development statuses of leaves, physical indexes, chemicalcomposition and neutral aroma constituents. And the key ecological factors offormation on quality of flue-cured tobacco were discussed. The experimentalconclusions were as follows.1、Analysis of quality of flue-cured tobacco upper leaves in Bijie region（1）Chemical composition of upper leafBijie area of upper leaves chemical composition generally showed aphenomenon of suitable sugar content, high starch and nicotine content. Totalnitrogen, potassium content and sugar base and the nitrogen base was relatively lowand chlorine content excessively low.The cluster analysis of chemical composition of upper leaves in Bijie region wasconducted with DPS software and the upper leaves of Bijie region was divided intotwo categories. Part I major categories of groups displayed partial higher nicotinecontent, relatively higher chlorine content, lower reducing sugar and total sugarcontent. Part II major categories group showed that nicotine content and chlorinecontent was relatively lower, reducing sugar and total sugar content was higher. Thecombination of elsvation for Bijie region obtained the phenomenon of high-nicotineand low-sugar in the low-elevation, high sugar and low nicotine in the high-elevation.In five Counties of Bijie region, the upper leaf chemical composition of thecoordination performed the worst in Bijie City, mainly showing in significantly highernicotine content, relatively lower content of reducing sugar, potassium, and sugar base.In Hezhang County and Jinsha County, the coordination was best mainly showing inbasically suitable reducing sugar content, nicotine and sugar base, but starch content was relatively higher, potassium and chlorine content lower.（2）Characteristics of neutral aroma constituents in upper leavesThe analysis showed that products degraded by carotene carotene, the productsof aromatic amino acid metabolism, the content of cembratriendiol group,neophytadiene and the total neutral aroma constituents in the upper leaves were higherthan in Qujing. The products degraded by carotene carotene, the products of aromaticamino acid metabolism, the content of cembratriendiol group, and products of the nonenzymatic browning reactant of upper leaves in Generous county were higher than theother counties. Generous county possessed favorable material base. The content ofneophytadiene and total neutral aroma constituent was highest in Hezhang contry, andit was more favorable to highlight the style of middle scent close to faint one tomiddle scent. In Weining contry, the content of cembratriendiol group was highest,and it is more favorable for increasing the faint scent aroma and fruity flavor intobacco leaves.2、Effects of elsvation on the growth and quality of flue-cured tobacco（1）The ecological characteristics on different elevationDuring the poriod of field growth the average temperature and rainfall isdecreasing with rising elevation, sunshine hours showed an increasing trend. Lowrainfalll in April, and low temperatures at high elsvations, the average temperature often days is less than15℃, is not conducive to transplanting; from May to June, therainfall increased, the temperature rose, the average temperature in the middle andhigh elevation lower than it in low elevation, and the low night temperature wasextremely unfavorable for the growth of tobacco seedlings; in July, suitabletemperature and abundant rainfall can meet the needs of growth and development oftobacco seedlings; in August and September, the rainfall gradually reduced and it wasconducive for leaves fall to yellow, but the increasing temperature difference betweenday and night would have slight influence on the baking quality.（2）Effects of elevation on the growth and development and physical indexes ofFlue-cured TobaccoWith the elevation rising, the transplanting period was delayed, the leaf size andthe number of effective leaves decreased, the leaf weight and leaf area after curingincreased. The temperature and humidity of low elevation was suitable for theimprovement of production quality and the development of tobacco leaves; in middleelevation, the upper leaves of Yun97spreading better, but the low temperature and drought before and after transplanting would block the speed of leaves and the leafnumber, the effective leaves decreased and the leaf weight increased; in highelevation, transplanting time and the period of field growth delayed, the tobacco lessaffected by low temperature with the whole laminating after transplanting, the leavesspreading better and the effective leaves were more than the leaves in the middleelevation, especially for the Yun97.（3）Effects of elevation on the chemical composition of different varietiesThe ecological conditions of different elevation had certain impact on thechemical composition of the tobacco leaves. The potassium and chlorine content ofthe tobacco leaves in Bijie was generally lower than the high quality tobaccoleaves.The content of nicotine, reducing sugar and total sugar of middle and upperleaves were higher in high-elevation. In low elevation, the content of nicotine, starch,reducing sugar and total sugar were slightly higher, the coordination of the chemicalcomposition was better than middle and high elevation; in middle and high elevation,the content of nicotine and starch was a bit higher and the total sugar was on the highside, which was harmful for the coordination of the chemical composition. The samevariety had different performance under different elevation, Yun87showed thecharacteristics of high sugar and low nicotine at lower elevation, but in the middleelevation completely contradict; Yun97showed the characteristics of high nicotineand lower sugar at high elevation, in the middle elevation completely contradict.（4）Effects of different elevation on neutral aroma constituentsThe neutral aroma constituents of the upper leaves in low elevatin were thehighest, the neutral aroma constituents of Yun87were higher than Yun97in low andhigh elevation; the neutral aroma constituents of upper leaves were higher in middleelevation, and Yun87higher than Yun97without exception. To the upper leaves, thecontent of neophytadiene, products degraded by carotene and total neutral aromacompotents were higher in mid-elevation, and the content of sugar and enzymesbrown fo degradation products and solanone were highest in low elevation. To themiddle leaves, the content of neophytadiene, carotene and the whole neutral aromacomponents decreased with the elevation increased, but the content of sugar andproducts degraded by enzymes increased with the elevation rising.