光照强度对白肋烟光合特性及中性致香成分的影响

Effects of Light Intensity on Photosynthetic Characteristics and Neutral Aroma Constituents of Burley Tobacco

以鄂烟6号为供试材料,在团棵期至成熟期通过人工遮阴,设置3种透光率水平(100%、80%、60%),探讨了不同光照强度对白肋烟光合特性和中性致香成分等理化性状的影响。结果表明,透光率80%处理小区的烟叶单位面积叶源量明显高于对照100%自然光照与60%透光率处理。在遮阴前期,光照强度起主要控制作用,遮阴处理的净光合速率较小(100%>80%>60%);而遮阴后期,遮阴处理小区环境温度较低,空气湿度与空气中CO_2浓度相对较高,叶片蒸腾速率与气孔导度增加,净光合速率高于对照100%自然光照(100%<80%<60%),胞间CO_2浓度降低。烟株对光照变化的适应性较强,长期遮阴能激发其对弱光的吸收和转化效率,透光率80%的中性致香成分、感官质量、非特异性过氧化物酶与超氧化物歧化酶活性整体均优于100%自然光照。但100%自然光强更能提高烟叶中水溶性糖含量,促进烟叶对水溶性氯、钾成分的吸收。总的来看,80%的光照条件下的烟叶品质更好,能满足工业企业的配方要求。

Toidentify theeffects of light intensity on photosynthesis of burley tobacco leavesduring field stages, andexplore the distribution differencesofmain neutral aroma constituentsincuredburley tobacco leaves of differentlight intensities treatment, artificial shadeexperiment with 3light transmittance level （100%, 80%, 60%） from rosette stage to maturation stagewas carried out by usingEyan 6 as testmaterial.The results indicated that leaf source capacity per unit area of 80% transmittance level was higher than the other two levels. In the early stage of the shade, light intensitywasthe majorcontrolling factor, net photosynthetic rate under shading treatment were lower than that under full sunlight（100%＆gt;80%＆gt;60%）;In the later period, environment temperature under shading treatmentwas lower, air humidity and CO2concentration was relatively high in the air, and stomatal conductance and transpiration rate increased, and net photosynthetic rate was higher than CK（100% transmittance level）,but the intercellular CO2 concentrationdecreased.Tobaccoleaveshada strong adaptability to light, and long-term shade couldstimulate its absorption and conversion efficiency of weak light. Neutral aroma constituents, sense quality, activities of peroxidase and superoxide dismutase were better thanthose of100% full natural light as a whole. But 100% natural light intensity was more advantageous to the increasing of content of soluble sugar, and absorption of water-soluble chloride and potassium in burley tobacco leaves. Through comprehensive analysis, tobacco leaves in 80% transmittance level havebetter quality and meet the formula requirements of the industrial enterprises.