UV-B辐射增强下种植密度对大麦生理特性的影响.doc

  UV-B 辐射增强下种植密度对大麦生理特性 的影响# 娄运生，曹畅* 5 10 （南京信息工程大学应用气象学院，南京 210046） 摘要：在大田条件下，以苏啤 3 号大麦为材料，研究 UV-B 辐射增强和种植密度对大麦生理 特性的影响。UV-B 辐射设置 2 水平：对照、增强 20%。种植密度（播种量）设置 3 水平： 50g/plot、100g/plot、和 150g/plot。结果表明，与对照相比，UV-B 辐射增强下大麦叶片的叶 绿素含量、净光合速率、气孔导度、胞间二氧化碳浓度、蒸腾速率和水分利用率均呈下降趋 势，随着 UV-B 辐射的增强，叶绿素含量和净光合速率呈较明显的递减趋势。在 UV-B 辐射 增强下，种植密度的增加使大麦叶片的叶绿素含量、净光合速率、气孔导度、胞间二氧化碳 浓度、蒸腾速率出现不同程度的降低。研究认为，提高大麦种植密度并不能明显减轻 UV-B 辐射增强对大麦光合和蒸腾作用的抑制作用。 关键词：应用气象学；UV-B 辐射增强；大麦；种植密度；光合作用 15 Effects of planting density on physiological properties in barley under enhanced UV-B radiation LOU Yunsheng, CAO Chang  20 25 30 35 40 (College of Applied Meteorology, Nanjing Information Science and Technology, Nanjing 210046) Abstract: The depletion of stratospheric ozone layer led to the enhanced UV-B radiation (280-320nm), which could influence physiological properties in crops. Reasonable planting density was helpful in optimizing group structure and increasing crop production. Barley is the forth most important worldwide cereal crop, after wheat, maize and rice, but very few studies have been conducted concerning its response to elevated UV-B radiation. Field experiment was conducted to investigate the changes of physiological properties in barley under enhanced UV-B radiation and different planting densities. The experiment was designed with two levels of UV-B radiation i.e. control (ambient), enhanced 20%; and three levels of planting density i.e. 50g/plot, 100g/plot and 150g/plot. The results showed that enhanced UV-B radiation reduced the chlorophyll content, net photosynthetic rate, stomatal conductivity, transpiration rate and water use efficiency in barley. Meanwhile, as the UV-B radiation increased, the tendency of decline in chlorophyll content, net photosynthetic rate was significant in the treatment group. With the planting density increasing, the chlorophyll content, net photosynthetic rate, stomatal conductivity, transpiration rate all decreased under enhanced UV-B radiation. It is suggested tha