| Sulfur is an important of mineral element for the crop growth and development next to N,P,K, and is the structural of many kinds of bimolecular,therefore plays an important role in stabilizing the cellular membrane structure, improving the protein metabolism and regulating enzyme activity. With the change of the tillage methods, tobacco sulfur nutrition has become an important factor to restrict tobacco production. Excess or shortage of sulfur both affect the growth of tobacco, thus reducing the yield and quality ,but sulfur nutrition of tobacco currently lack a comprehensive system of high-sulfur and low sulfur environment research, and do not have a sulfur nutrition diagnostic indicators. Based on this background, this research was carries out with the varieties of high quality tobacco as the research object, and sand culture experiment at four S levels were conducted to observe and explore their differences in Physiological and biochemical indicators of tobacco, ultrastructure changes of the cells in sulfur stress were examined by electron microscopy. Analysis of the distribution of sulfur in tobacco and the effects of the absorption of other nutrients .Explore the rule of needs for growth of the tobacco and primarily establish nutrient diagnosis indexes of the Sulfur nutrition of tobacco. Main results are as follows:1 Sulfur treatment on the inhibition of plant height significantly. Deficiency treatment reduced significantly tobacco diameter, high-sulfur treatment on the stem base not significant. The diameter was significantly higher at Deficiency treatment properly. Applied S fertilizer can increase the tobacco leaf blade width; high-sulfur stress, the rosette of dark green leaves and leaf growth is slow. When sulfur supply was 0.6g/pot, the tobacco plant growth were increased, 1.2g/pot on growth inhibition was not obvious.2 The chlorophyll content and SPAD were decreased when sulfur supply was too high or too low. The chlorophyll content was significantly higher at high-sulfur treatment in spherical plant stage, high-sulfur treatment had no significant influence on Fluorescence Measurement and Photosynthesis in later stage of growth. Pn,Ci,E of low-sulfur treatment was higher than that of control. The Photosynthesis under 2.4g/pot was significantly lower than under other treatments.3 Effects of S have reduced the soluble protein content and nitrate reductase activity, sulfur stress treatments restrained the process of nitrogen metabolism by decreasing the activity soluble protein content of and nitrate reductase activity in leaves.4 Treatment of tobacco leaves and roots of cell structure was different: the tobacco chloroplast dysplasia, and the expansion of chloroplast grana lamellae disintegrated; mitochondrial membrane was not clear, based less liquid; root cell wall and cell membrane were not clear, more inclusions less, root cell mitochondria, the outer membrane are not clearly. When the amount of sulfur applied 1.2g/pot, the tobacco plant can grow normally, but the cell structure was different from the control. High-sulfur stress made the chloroplast exhibits swelling deformation; number of stacks and thickness of thylakoids of grana were increased. Mitochondria structure of root was not obvious; cell membrane of root was thinner and smaller than control.5 Sulfur supply could significantly increase tobacco sulfur content, and the sequence of sulfur content is: leaf>root>stem, but the sequence of the absorbing sulphur is : leaf> stem > root.6 Low-Sulfur was significantly higher than under other treatments at increased tobacco the nitrogen content. The sequence of the nitrogen content is : leaf> stem > root at 0-0.6g/pot treatments, while the sequence of the nitrogen content of high- sulfur is : leaf> stem > root at 0-0.6g/pot treatments.7 Low-Sulfur was significantly higher than high-sulfur stress treatments at increased tobacco the P content.8 The sequence of K content is: leaf> stem > root, Potassium content in different parts of the trend were significantly different, with the treatment level increased, the potassium content decreased tobacco roots, while leaves as increased. Sulfur supply could contribute to the absorption of potassium. 9 As the increase in the level of sulfur, the N/S was significantly decreased; N/S of control is 30.84 in sand culture experiment. Analysis shows N/S have a significant relation with the sulfur content of leafs (P<0.05).
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