Study On Difference Of Tobacco Leaf Microstructure And Metabolic Products And Effect Of Light

Tobacco is an important economic crop, also an important model plant for studying. It plays a pivotal role in social economy and natural science. Studies have been conducted on leaf structure and metabolic products under breeding, leaf position various maturities and effects of light. Then spongy and palisade cells was divided by pectinase, and metabolic products of palisade cell and spongy cell and the effects of light on leaf was also detected.1. The structure tied up to breeds, leaf position and maturity. The leaf thickness was determined by spongy thickness. Leaf thickness, palisade/spongy mesophyll, density of cells and spacing were evidently different, but the density, breadth and thickness of epidermal was little difference. It was showed in leaf structure that upper leaf was thinnest and the cell density was biggest and the intercellular space degree was least; cutters was thickest, the cell density and intercellular space degree was moderated; The thickness of lower leaf was moderated, and its cell density was least, and its intercellular space degree was biggest. So the standard maturity of different leaf position was different. The density, structure and chloroplast number of stoma was relation to leaf position. It was some different between K326 and HD maturing process .While maturity thickness of leaf, length of palisade cells increased gradually, then declined, spacing of leaf increased gradually. So the structure of ripe leaf loosened properly, and it made for tobacco quality. The maturing process was different between K326 and HD, and the maturity was different in breeds. The structure of stoma stabilized, but function fall during maturing, and the number of chloroplast in guard cell drooped, and it might be a reference for maturing.2. The category and content of metabolic production was also tied up to breeds, leaf position and maturity. Only could Oxalic Acid be detected in HD. The metabolic production was in line of cutters, and the quality was best, but the content of polyphenol in bottom leaf and the content of carotenoid in lower leaf was highest, and it was propitious to tobacco quality. The content of element of ripe leaf wasn't all high. But carbohydrate accumulated little and element was out of line in unripe or mature leaf. Dry matter accumulated enough, and the content of sugar and nicotine of unripe leaf was more. The ratio of sugar to nicotine was happy, and element was in line, the quality was best. Metabolic production consumed tanto, quality was worst.3. The spongy and palisade cell of leaf. Tobacco was typical bifoliolate leaf and spongy cell was exposed firstly if the abaxial was divided. The spongy and palisade cell of leaf was divided by 5% pectinase with cell membrane stabilization liquid. It would be treated more time if leaf was early maturity or high leaf position.The content of total sugar, deoxidize sugar, starch, pigment(chlorophyll and carotenoid), citric acid, malic acid, polyphenol of palisade cell was higher than that in spongy cell, but the content of nicotine, oxalic acid, palm acid of spongy cell was higher than that in palisade cell. The entire element in cell was higher than in intact leaf. It was a good way to culture palisade cell developed measurably for improving tobacco quality.The change rule of palisade or spongy cell from different breeds, leaf position and maturity was familiar to intact leaf, but it changed more.4. Effect of light on tobacco young stem.UV lead young tobacco be dwarfism and sturdy, area of leaf, photosynthetic rate(Pn),content of chlorophyll, sugar and nicotine declined, andβ-carotenoid, total carotenoid, polyphenol increased. The content of chlorophyll, carotenoid, sugar, polyphenol in palisade cell was more than that in spongy cell, and the content of nicotine contrary to it.Blue and red light would restrain stem length, but the effect of green and yellow light contrary to it. Only blue light could increase Pn, blue could increase the content of chlorophyll, but all light quality declined the content of carotenoid.The content of sugar would higher if treated under white and red lights, even content of total sugar would exceed the control if treated with red. The content of deoxidize sugar treated with any light quality exceeded the control, and the content of nicotine declined in red or yellow, and the polyphenol increased in red.Plant height, deoxidize sugar and nicotine was negative correlation to light strength, and stem diameter, leaf length or broad, Pn, content of chlorophyll and carotenoid, total sugar, polyphenol was positive correlation, and middle light strength did goods to taproot growth. The effect of light strength on carotenoid and deoxidize sugar in spongy cell was more obviously, and the total sugar in palisade cell changed more because of filtration of epidermis and palisade cell...