Influence On Growth And Quality Of The Flu-cured Tobacco In The Field Stage With The Different Light In The Seedling Stage

light condition is one of the main factors influencing the aroma style, yield and quality of tobacco.It will have a great theoretical and practical significance to study on effects of light quality and the light intensity in seedling period to growth and physiological indexes in field growing season and the aroma style with highly flavored type of flue-cured tobacco. This paper was aimed to systemic research the influence on agronomic traits of tobacco plant in field growing season and quality of the flue-cured tobacco leaves which tobacco seedlings cultivated under the different light conditions before transplanted to field. The purpose is to provide theoretical and experimental basis for revealing the relation between the flue-cured tobacco style formation on highly flavored type of Hunan tobacco and the light quality and intensity. The main research results of experiment are as follows:1、The observed results of K326tobacco plants growing in the field showed that it had little effects on the growth period of tobacco plant by cultivating tobacco seedlings under different light quality and intensity, but a certain influence on the agronomic traits and physiological indexes of tobacco plants in the field. Cultivating tobacco seedlings under the condition of red-ray:blu-ray3:1, the growth speed, plastid pigment and reducing sugar content of tobacco leaves in the field were greater than them of growing seedlings under the condition of blu-ray:red-ray3:1, though,root activity, nitrate reductase activity and protein content of tobacco plants for growing tobacco seedlings under the condition of blu-ray: red-ray3:1were significantly greater than red-ray:blu-ray3:1. Increasing the light intensity at the seedling stage was advantageous to chlorophyll synthesis of tobacco leaves and improved root activity of tobacco plants in the field.2、The analysis results of the flue-cured tobacco K326quality showed that the leaf length, leaf-enlarging degree, single leaf weight, stem ratio and mass per unit leaf area of upper tobacco leaves by cultivating tobacco seedlings in different light quality and intensity were significantly greater than the contrast, but extremely less than the control for them of middle tobacco leaves. Influence on chemical index of the flue-cured tobacco cultivated tobacco seedling under different light quality and intensity were mainly concentrated upon saccharides and secondary metabolites, and also showed up leaf position difference. 3、The observed results of tobacco plants growth from Yunnan Kunming K326tobacco seedlings transplanting in field of Hunan south showed that tobacco seedlings cultivated under high light intensity and high temperature conditions in Yunnan Kunming, the time of flowering, lower leaves turning yellow and the top leaves reaching full ripeness of tobacco plants from Kunming seedlings were delayed somewhat than them from Guiyang local seedling, and plant height, stem circumference, blade width, pitch, leaf numbers of physiological and effective number of tobacco plant from Kunming seedlings were higher than them from Guiyang local seedlings. The content of chlorophyll a, total chlorophyll, carotenoid, protein and ratio of light energy utilization were higher than the tobacco plants from Guiyang local seedlings.4、The analysis results of the flue-cured tobacco quality from Yunnan Kunming K326tobacco seedlings transplanting in field of Hunan south showed that volume of the flue-cured tobacco leaves from Yunnan Kunming seedlings were less than it from Guiyang local seedlings. Influence on physical index of the flue-cured tobacco to cultivating tobacco seedlings under different light and temperature conditions not only existed leaf position difference,but also to middle and upper tobacco leaves were greater than lower tobacco leaves.5、Cultivating tobacco seedlings under different light and temperature conditions, even at the same time, transplanting to the same ecological tobacco field growth, also had a greater influence on the chemical index of the upper, middle and lower tobacco leaves, especially effects greatly to carbohydrate compounds and secondary metabolites such as the content of carotenoids, chlorogenic acid, as well as related to quality index such as difference of two sugar, the ratio of sugar alkali and potassium chloride. and that the content of the total sugar and reducing sugar, the ratio of sugar alkali and potassium chloride of the flue-cured tobacco from Kunming seedlings were lower than them from Guiyang local seedlings, but the carotenoid and polyphenol of the flue-cured tobacco from Kunming seedlings were higher than them from Guiyang local seedlings.