Interaction Effects of Light Intensity and Nitrogen Supply on Gas Exchange, Some Enzyme Activities in Carbon-Nitrogen Metabolism and Quality in Flue-Cured Tobacco
Year: 2010
Type: article
Abstract: As a main nutritive element of tobacco, nitrogen not only plays an important role in protection against light stress, but also impacts on the balance of carbon-nitrogen metabolism.The combination of proper light intensity and nitrogen application could improve the utilization of light energy and increase the amount of dry matter accumulation in flue-cured tobacco.The objectives of this study were to reveal the interaction effects of light intensity and nitrogen application on gas exchange parameters, some enzyme activities in carbon-nitrogen metabolism and chemical composition and to investigate the optimum combination of light and nitrogen in tobacco growth.Flue-cured tobacco Yuyan 5 was used in a pot experiment in 2008, with the treatments of light intensity (four levels) and nitrogen supply (three treatments).The results indicated that the net photosynthetic rate (P n ), transpiration rate (T r ), stomatal conductance (G s ) and the amount of dry matter accumulation reduced under shading, but the intercellular CO 2 concentration (C i ) increased.Light, nitrogen and their interactions had a significant influence on photosynthetic physiology indicators of flue-cured tobacco.The decline in photosynthetic rate caused by shading could be effectively improved by appropriate application of nitrogen so that the photosynthetic capability and the dry matter accumulation of tobacco could be promoted, but over-application of nitrogen had a negative influence on photosynthetic efficiency.With increasing the rate of nitrogen, the activity of nitrate reductase increased and reached the maximum at 40 days after transplant for N1, N2, and 60 days after transplant for N3, showing that the nitrogen metabolism was postponed.The results also showed that the contents of total nitrogen and nicotine increased with increasing the rate of shading and nitrogen, but the content of carbohydrate reduced.Generally, the nitrogen metabolism was likely stronger than the carbon metabolism.Light, nitrogen and their interactions had a significant influence on flue-cured tobacco.The combination of 70% of natural light intensity and proper application of nitrogen (N2, 3.5 g per pot in this experiment) could improve the photosynthetic capability and the balance of carbon-nitrogen metabolism, and increase the amount of dry matter accumulation and the quality in flue-cured tobacco.
Source: ACTA AGRONOMICA SINICA
Authors: Fei YUN, Guo-Shun LIU, Hong-Zhi SHI
Institution: Henan Agricultural University
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2005990195