Zhou Jiheng

Effect of UV-B on growth and development and secondary metabolism of flue-cured tobacco.

By the cointegration method,the influence of sugar futures price in Zhengzhou commodity exchange on the Nanning sugar stock price was investigated based on the data from April 24,2007 to December 29,2008.The result shows that there is co-integration relation between the Nanning sugar stock price and the sugar futures price;the sugar futures price is Granger causes of the Nanning sugar stock price,but the Nanning sugar stock price is not Granger causes of sugar futures price;and in the short term,the Nanning sugar stock price and the sugar futures price are mainly influenced by themselves.Conclusions: 1)sugar futures market has hedging and price discovery role;2)the two functions of sugar futures market,hedging and price discovery,are interacted with characteristics of time delay.The suggestion is that China should speed up the development and improvement of the white sugar futures market building.

Effects of Intensified UV-B Radiation on Main Aroma Precursors and Chemical Components in Flue-cured Tobacco

In order to investigate the reasons for the formation of aroma style of quality tobacco leaf and the accumulation of aroma components in flue-cured tobacco,the contents of aroma precursors,including plastid pigments(chlorophyll,lutein,β-carotene) and polyphenols(chlorogenic acid,rutin),and total sugar,reducing sugar,total nitrogen,protein,nicotine,potassium in the upper and middle leaves of flue-cured tobacco exposed to natural light with higher UV-B intensities were determined.The results showed that the synthesis of plastid pigment in upper leaves was suppressed,while that in middle leaves was promoted by intensified UV-B radiation;however,the synthesis of polyphenols was on the contrary.The contents of total sugar,reducing sugar,total nitrogen,protein and nicotine in upper leaves and total sugar and reducing sugar in middle leaves were decreased,while potassium content in upper leaves and the contents of total nitrogen,protein,nicotine and potassium in middle leaves were increased by intensified UV-B radiation.The main aroma precursors and chemical components in flue-cured tobacco were closely correlated to the intensity of UV-B,proper UV-B intensification would improve the aroma and quality of middle leaves of flue-cured tobacco.

Physiological response ability of different flue-cured tobacco varieties to UV-B radiation

A pot experiment was carried out to explore the response ability and mechanism of flue-cured tobacco to UV-B radiant intensity using varety Hongda and K326 as material.The tobacco agronomic characteristics,the contents of photosynthetic pigment and polyphenols,the vigor of root system and the activities of the antioxidant enzymes were determined.The result showed that tobacco height,the contents of chlorophyll A,chlorophyll B,total chlorophyll,lutein,carotene,chlorogenic acid and rutin were improved.The activities of both POD and root dehydrogenase were more higher compared to the control group while CAT was lower comared to the control group.And the biggest increase of pigments is lutein,then carotene and chlorophyll B,and finally chlorophyll A.The increase of the content of rutin was larger compared to that in chlorogenic acid.The range of variation of antioxidant enzyme activity increased with radiant intensity increased.It suggested that flue-cured tobacco can adapt to UV-B radiation enhancement by adjusting the contents of light oxidation resistance substance and antioxidant enzymes activities.Furthermore,a large difference of the response ability to UV-B radiation existed between two flue-cured tobacco varieties.And that of Hongda was much stronger than that of K326.

Effects of N,P,K,Mg Deficiency on Plant Growth and Leaf Glandular Trichome Development of Flue-cured Tobacco

Using flue-cured tobacco cv.K326 as material,the plant growth and leaf glandular trichomes development of flue-cured tobacco in the deficiency of nutrient elements during plant growing were studied.The results indicated that a deficiency of N,P,K,Mg not only negatively affected the growth of tobacco plant,but also had a significant effect on the growth and development of leaf glandular trichomes.N deficiency would decrease leaf area and stimulate the growth of various glandular trichomes,and the density of glandular trichome increased accordingly,while P,K,Mg deficiency would reduce the density of glandular trichome greatly besides leaf area reduction.Therefore,sufficient P,K,Mg nutrients application in the early growth stage of tobacco plant is particularly important for enhancing glandular trichome density and glandular secretion of tobacco leaves.

Effects of Seedling Hardening at Different Water Levels in Float System on Growth,Development and Physiological Characteristics of Flue-cured Tobacco Plant

In order to find a solution to the problems of slow restoring and poor drought tolerance of flue-cured tobacco seedlings in float system,the experiment of seedling hardening at two different water levels:low water level (the bottom of seedling tray touching on the water surface) and extra-low water level (the bottom of seedling tray over the water surface by 5cm) was conducted by using conventional float system practice as the control. The results showed that:the biological characteristics of seedlings in low water level treatment were better than that in extra-low water level treatment,both treatments were better than the control. The restoring rate,root system vigor,nitrate reductase activity,photosynthetic rate and chlorophyll content of tobacco seedling were better in extra-low water level treatment and good in low water level treatment.

Major Factors Affecting Adventitious Roots Development in Flue-cured Tobacco Plants

With flue-cured tobacco cv.K326 as test material, 4 treatments (moisture retention, shading, leaf removing and 10-4mol/L IAA spraying) were respectively carried out at the base site of stem, and the effects of moisture content, light and IAA applying on the development of adventitious roots in flue-cured tobacco plants were studied. The results indicated that moisture content and light had important effects on the formation of adventitious roots, furthermore, the moisture content was the key factor on which the growth and activity of adventitious roots heavily relied. Applying IAA and removing lower leaves could increase the number and activity of adventitious roots.

Quantitative Analysis and Evaluation of Smoking Quality of Flue-cured Tobacco Grown in South Hunan

To all-sidedly investigate the regional quality characteristics and industrial usability of flue-cured tobacco grown in South Hunan,186 flue-cured tobacco samples from 10 main flue-cured tobacco growing counties in South Hunan were quantitatively analyzed and evaluated by sensory smoking and statistical analysis.The results showed that the compatibility and industrial usability of the tobacco samples were good,the smoking quality of the majority of tested tobacco(B2F,C3F and X2F) was up to the standard of Class A.The proportions of premium flavor grade,flavor grade and filler grade in all samples were 31.7%,38.1% and 29.7%,respectively.The smoking quality of the tobacco extremely significantly differed between stalk positions,some indexes of smoking quality significantly differed between different crop years,while there was no significant difference in smoking quality between cultivars or counties,except aroma.

Chlorine Content in Hunan Flue-cured Tobacco and Its Effects on Smoking Quality

The chlorine content in Hunan flue-cured tobacco and its effects on smoking quality were analyzed. The results showed that there was no significant difference between the chlorine contents in tobacco grown in different areas of Hunan, the chlorine content was low in general with only a few exceptions. Correlation analysis indicated that chlorine was significantly positively correlated to aftertaste and significantly negatively correlated to ash color. The smoking quality index in order of grey incidence degree with chlorine was irritationoffensive odorash colorcombustibilityaftertastetasteimpacttotal scorearoma qualityflavoraroma quantityconcentration. The effects of chlorine contents on smoking quality differed, lower chlorine content would reduce aroma, taste and deteriorate smoking quality. Proper chlorine supply once every two years in the areas where chlorine content in tobacco leaf was lower was recommended.

Surface Characteristics and Main Chemical Composition of Flue-cured Tobacco Seed

In order to investigate the relationships between surface appearance and chemical components of seed from flue-cured tobacco of different varieties with their genetic parent,the seed surface characteristics were observed and compared,and the contents of protein and higher fatty acids in seeds were analyzed.The results showed that the seeds with close genetic relationship possessed some similarities in their appearances.The main compositions in seed were protein and fat,and unsaturated fatty acids dominated the constitution of the fat.The contents of protein and fatty acids in seeds differed remarkably between different varieties.