Study On Effect Of Light Intensity On Growth And Leaf Tissue Structur And Quality Characteristic Of Flue-cured Tobacco

In 2007, artificial simulated through three light intensity studied K326 and Hongda seedlings under different light intensity in the growth and changes of physiological indexes.2009 in ancient MaLong tobacco area through three light intensity gradient under field planting, studied Hongda and Yun87 flue-cured tobacco growth and quality and structure. Main research results are as follows:1.K326 and Hongda seedling high increase, stem decreased, seedling morphological were slim under relatively weak light. Seedlings leaves, leaf length decreases with the light intensity decreased. The light intensity of medium height promote taproot to growth, but taproot growth was inhibit with the light intensity decreased to a certain extent. With the light intensity decreased, seedlings photosynthetic capability weaker, carbohydrate accumulation reduced. Effect of light intensity in two varieties had differences; Hongda seedlings changes were more sensitive. Morphological and contains material changes under low light intensity to bring about quality of tobacco seedlings in floating system decreased.2. Birth process of Yun 87 and Hongda were more slow under low light intensity. Hongda were more sensitive.60% of light intensity greatly increased growth days,more than natural light intensity 13 days. With light intensity decreased the height of tobacco increased, stem decreased. Tobacco leaf numbers and effective leaf numbers decreased with the light intensity decreased the lower light intensity the less leaf tobacco plants. Dry matter accumulations of flue-cured tobacco were reduced with light intensity decreased. Under the weak light yield and production value were reduced. Hongda yield and production value dropt more severely, felt to 35.33% and 53.37%.3. Tobacco stomata and microstructure observation results show that:Yun87 and Hongda fresh leaves the somatic distribution and size were difference. With the illumination intensity decreased, width of stomata reduced on leaf epidermis. Stomata size under 80% natural light treatment>60% natural light intensity treatment> natural light intensity treatment. Leaf tissue structure of Yun87 research shows that:With the light intensity decreased, leaf thickness increased but epidermis and lower epidermis thickness reduced. Sponge tissue thickness were reduced, Stockade tissue thickness increased.4. The result of physical properties in flue-cured tobacco leaves showed that:with the decrease of light intensity, length and width of upper leaf and middle leaf increased except lower leaf had no variation rules. Leaves thickness of leaves in three parts were consistent. With intensity decreased, Leaf density decreased. With different light intensity, the quality in different leaf parts were diffrerent.Upper leaves with light intensity decreased were significantly reduced, middle leaves were significantly increased, lower leaves no obvious rule. Light intensity had no obvious effect to contain rate of stem, all contain ratio of stem between 20-38 percent. With light intensity decreased leaf industrial usability tend to stuffing.5. Chemical constituents content were different under different light intensities. Total sugar, sugar content decreased with light intensity. Nicotine, chlorine, nitrogen and potassium content is increased with the decreasing intensity. Sulfur and phosphorus changes without obvious rule. Chemical compatibility with light intensity decreases, nitrogen, sugar than alkali chlorine alkali ratio, potassium ratio. Some important premise with aromas of physical intensity decreased with. Overall, low quality of flue-cured tobacco intensity to decline. And low intensity of Hongda leaf quality than on influence over Yun87.