Oriental Tobacco Leaf Cells Ultrastructure Analysis And Curing Technologies Research

In 2006-2007 ,through field trial in Zhejiang for oriental tobacco research. Studies on leaf cell growth and development of oriental tobacco, the curing technologies and the quality factor of oriental tobacco in the curing process were also studied, the results showed that:1. The ultrastructure changes of leaf cells in development and curing process of oriental tobacco(1) Leaf surface oil material mainly by the degradation of epidermal cells through, then use the multivesicular body transported to the outer membrane cells, finally secrete to the leaf surface.(2) The chloroplast in leaf cells is the important part of starch and osmiophilic material compound place. The leaf cells in the cell division and cell development stage before leaf 5 cm long, after 15 cm long the cell into the function stage, the number of chloroplast increase, the chloroplast began accumulating starch grains and entrain osmiophilic granules, when leaf 20 cm long, cell function is vigorous, in cells chloroplast dark osmiophilic granules increased, and around the nuclear and chloroplast the endoplasmic reticulum developed, the number of mitochondria increase, a larger number of gray osmiophilic granules around the mitochondria, and transfer into the vacuole, finally in the vacuole formed into dark osmiophilic granules; when leaf length 22 cm, the cells starch accumulated, chloroplast start to degradation, cell function began recession. Tobacco mature to a stage of maturity, the organelle gradual degradation and disappear, with the starch grains degradation in the cell, formed a lot of gray osmiophilic material and ultimately the entire vacuole is full of gray osmiophilic material accumulate around the starch grains.(3) The leaf length from 5 cm to 20 cm, with the development forming of oriental tobacco leaves, the number of chloroplast grana lamella increased, and the photosynthetic rate increase gradually. When leaf length 22 cm, the number of chloroplast grana lamella reduce rapidly, the photosynthetic rate also decreased rapidly, until the harvest time, chloroplast has almost disintegrated and disappeared.(4) The cell division mainly before 9 days, the leaves have begun with photosynthetic capacity after 9 days, then the cell with the low ability in division, leaf cells enter the functional period in 19 days and begin to enter the assimilation of accumulation period in 26 days; In Yellowing stage the organelle disappear, and starch grains were still decomposed, in stem-drying stage cell wall started contraction, cells contain large quantities of lipid material and some starch grains with no degradation. Nitrogen metabolism mainly in 0-23 days, the carbon metabolism starting from 19 days. According to the research that the oriental tobacco should be given adequate fertilizer supply before 23 days; and extend the yellowing stage can be fully decompose starch, increase the sugar content of tobacco leaves.2. Maturity grades effect on quality of oriental tobacco in curing processWater content of tobacco leaves decreased with curing time, the higher the leaves maturity degree was, the faster water content decreased. Contents of chlorophyll and carotenoid tended to decrease during curing process. And proper matured leaves discomposed most completely among all treatments. Contents of starch and soluble protein of proper matured leaves were lowest. Contents of total sugar, protein and CL of over matured were lower than those of under matured and proper matured leaves. Contents of major chemical components of proper matured leaves were closer to the standard of high quality oriental tobacco, such as contents of total nicotine, nitrate,total nitrogen ,protein and K. So it is proper to pick the upper leaves when they are proper matured.3. Curing method effect on quality of oriental tobaccoThe content of soluble protein and starch of tobacco leaves cured in plastic shed was lower than those cured in traditional way. The content of nicotine, total nitrogen, protein intended to increase during the curing process and the final content of nicotine, total nitrogen, protein of tobacco leaves cured in plastic shed was lower; The content of total sugar intended to decrease and the final content of two treatments were same; The pigment discomposed during the curing process . The content of chlorophyll discomposed faster than carotenoid. The final content of carotenoid was higher than chlorophyll.4. Airing time effect on quality of oriental tobaccoThe contents of chlorophyll and carotenoid decomposed following the curing time. The carotenoid had lower rates of decomposition, which might have positive effects on the leaf quality; the content of total sugar, total protein and amylum intended to decrease during the curing process, the content of dissociative aminophenol and volatile alkali intended to increase. The chemical composition of the leaves air-cured for one or two days was coordinative and high quality.