遮阴对烤烟叶片结构和中性致香物质含量的影响

Effect of Shading on the Leaf Structure and Neutral Aroma Components of Flue-cured Tobacco

[目的]研究不同光照强度对烟草生长发育和品质的影响,为培育合理的株型、确定适当的栽培密度和烟草品质与生态关系提供科学依据。[方法]以云烟85为供试品种,通过盆栽试验,用遮阴网营造不同的光照环境(覆盖1层遮阴网,约透光50%;覆盖2层遮阴网,约透光25%),研究了遮阴对烤烟叶片结构、光合性状和中性致香物质含量的影响。[结果]随着遮阴程度的增加,烟草叶片组织厚度、光合速率、蒸腾速率和气孔导度降低,而胞间二氧化碳浓度升高,烤后烟叶中性致香物质含量增加。致香物质多为烟草叶片次生代谢产物,而光照对植物次生代谢有重要的调控作用。[结论]遮阴改变了烤烟生长的光照条件,因而影响烟株体内生理代谢和次生代谢产物生成。

[Objective] The purpose was to study the effect of different light intensity on the growth and quality of flue-cured tobacco and provide the scientific basis for breeding the reasonable plant type, determining the appropriate planting density and the relationship between quali- ty of flue-cured tobacco and ecology.[Method] In the pot experiment, with Yunyan 85 as tested cuhivar, the shade nets were uscd to build different light environments as covering 1 layer shade net and light transmission about 50% and covering 2 layer shade nets and light transmis- sion about 25% so as to study the effect of shading on leaf structure, photosynthetic characters and neutral aroma components.[Result] With the enhanced shading degree, the thickness, photosynthesis rate, transpiration rate and stomata conductance of flue-cured tobacco leaves were decreased, but thc intercellular CO2 concentration and the neutral aroma components in cured tobacco leaves were increased. The flavor matter was mostly secondary metabolites in leaf of tobacco and the light had an important regulatory effect on plant secondary mctabolites. [Conclusion] Shading had changed the light condition for flue-cured tobacco growth, thereby affected the physiological metabolism in vivo and generation of secondary metabolites of the tobacco plant.