Relationships Between Soil Ecological Factors And The Distinguishing Luscious Feature In Flue-Cured Tobacco Leaves In Wannan Tobacco-Growing Areas

A number of experiment sites were selected in the main tobacco-planting regions in southern Anhui province from 2006 to 2007 , to study the soil physical and chemical characteristics , soil microbes, the contents of aroma components ,the expression of flue-cured tobacco aroma,under the different ecological conditions of soil,and further the relationships between the aroma expression characteristics and soil ecological characteristics , the method of statistical analysis were employed . the results were as follows:1. The primary investigation of micro-organisms population in different category tobacco-planting fieldAn experiment was carried out in south of Anhui province to study soil microbe categories and relative numbers of four kinds soil system (bottomland, alluvium, paddy clay and alluvion sand) in tobacco life cycle. The main results are as follows: no matter in rooted or non-rooted soil, the bacteria, fungi and actinomycetes are main categories which gross numbers are more than 95% in all soil microbe mounts. During the flue-cured tobacco life cycle, the non-rooted microbe gross number was less than the rooted's, moreover the difference of each soil microbe number and variety index are much obvious. By analyzing the soil microbe of these four category soil, primary discussed the relationship between soil nutrient contents and soil microbe numbers, the numbers of most kinds microbe have positive correlation with soil nutrient contents.2. The research on soil microbes dynamics in four type soilTo discuss and analyse the characteristic and transformation rule of microbes in flue-cured tobacco life cycle in four type soil (bottomland,alluvium sand,clay,bottomland sand),the difference of microbes between kinds of soil in four periods have been identified .the result showed that: microbes amounts in four kinds soil are all not only different in each periods,but among four types soil in same periods are also distinct, however, the most significant diversity appears in vigorous-growing periods. most kinds microbes in rhizosphere-soil have significant correlation, linear regression analyse kinds of soil microbes, demonstrated that certain co-operative microbial activities can be exploited, most Soil microbial populations are immersed in a framework of interactions . the microbes dynamics rule in tobacco life cycle of different kinds soil might be as a new index to analyse the reason how tobacco features were shaped.3. Effect of soil type on microbe community composition in rhizosphere and bulk soil of flue-cured.To dicuss the characteristic of microbe community composition in rhizosphere and bulk of flue-cured life cycle in four type soil,the study was carried out in south of Anhui province ,and the technical of denaturing gradient gel electrophoresis (DGGE) of 16S rDNA was adopted after vigorous periods. the result showed that: the total number of bacteria,fungian,dactinomyces of rhizosphere and bulk began to rise at planting and quickly reached it`s peak at vigorous-growing period, but decreased significantly late. PCR was employed to amplify V3 region of 16SrDNA , then the products were subjected to denaturing gradient gel electrophoresis(DGGE).DGGE profile indicated that, difference was observed at vigorous-growing period of four type soil Significant, while became unconspicuous at mature period , all the difference especially obvious in rhizosphere .otherwise, the same and differential bands in DGGE patterns of different soil, might be as a new index for flue-cured growth and quality.4. Studies on the aroma components in tobacco from Wannan and different flue-cured tobacco production regions with ZimbabweFor discuss the aroma components difference between domestic Flue-cured Tobacco Production Regions with Zimbabwe, the multiple discriminant analysis (MDA)method was used for each region aroma type pattern recognition. The result showed that the dominating differentia components were Furfuryl alcohol, 2-Acetylfuran, Phenylethanol, Megastigmatrienone D, Methyl palmitate in areas. The contents of aroma components in domestic each region was not significantly different, however, it is obvious when compared with Zimbabwe`s. The aroma type in Wannan are similar with Guangdong and Yunnan regions even more, in addition ,the aroma type of upper tobacco leaves in Wenchang area has high similarity with Zimbabwe.5. The research on positive aroma components selection in Wannan flue-cured tobacco production regionsAccording to the evaluation made by industry, the index which included the aroma quality, aroma volume, and the luscious characteristics were selected to classify the flue-cured tobacco distinguishing aroma feature because of their important function in aroma behavior appraisal .by means of the multiple discriminant analysis (MDA)method ,the classification foundation was found ,that is the dominating differentia components. the aroma quality classification components included Chlorine, furfural, FA, 6 - methyl -5 - heptene -2 - alcohol, benzyl alcohol, 2 - acetyl pyrrole ,linalool, and Megastigmatrienone D; the aroma volume classification components included total sugar, chlorine, FA, 6 - methyl -5 - heptene -2 - one, benzyl alcohol, linalool; the luscious characteristics classification components included K,6 - methyl-5 - heptene -2– alcohol,benzyl alcohol,indole,solanone,Megastigmatrienone B,3-oxo-α-ionol.6. Research on the relationships between the major contribution components of flue-cured tobacco aroma and soil nutrientThe influence of the mineral elements which impacted on the aroma behavior of flue-cured tobacco are more significant than the conventional soil nutrient, in other words , the elements contents such as P,Fe,Al,Ca in soil and soil type(sandy status ) have more important function in formation local flue-cured tobacco aroma characteristics, their contents and level were positive correlation with the beneficial aroma components of tobacco in some sense. However, the conventional soil nutrient such as organic matter, available N were not so important as the mineral elements in the process of tobacco aroma characteristics formation, further ,the influence of available K and available P are good in parts ,but both of them can reduce the contents of indole and chlorine in flue-cured tobacco.