UV-B辐射增强对大麦生理生态的影响

Effect of Enhanced Ultraviolet-B Radiation on Physiological and Ecological Parameters in Barley

在大田条件下,研究了UV-B辐射增强对大麦的生长发育、光合作用、蒸腾作用及其产量构成的影响。结果表明,UV-B辐射增强明显抑制大麦生长,使株高变矮、绿叶数减少、叶面积和干物质量下降,但抑制程度随生育期而异。在UV-B辐射增强条件下,大麦叶片叶绿素含量、净光合速率、气孔导度和蒸腾速率都有不同程度的降低,水分利用率也随之降低。UV-B辐射增强对大麦形态学和生理学上的不利影响,导致了大麦产量下降24.96%。

The stratospheric ozone layer formed a protective atmospheric filter against biologically harmful solar ultraviolet（UV）radiation.Anthropogenic emissions of chlorofluorocarbons and nitrogen oxides resulted in depletion of ozone layer.Consequently,enhanced levels of UV-B radiation（280～320 nm）had been detected in the Southern as well as in the Northern Hemisphere.Enhanced UV-B radiation had been confirmed to negatively affect plant growth and development in higher plants.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 with barley was conducted to investigate the changes of growth,development and yield under enhanced UV-B radiation.The experiment was designed with two levels of UV-B radiation i.e.contro（lCK,ambient）and enhanced UV-B（E,1.8 kJ·m-2）,and conducted at the Agro-Meteorological Station,Nanjing University of Information Science and Technology,Jiangsu Province,China.The results showed that the decreases in plant height,green leaf number,total leaf area and biomass（root and shoot）were observed under enhanced UV-B radiation,but varied with growth stages.Furthermore,enhanced UV-B radiation also reduced chlorophyll content,net photosynthetic rate,stomatal conductivity,transpiration rate and water use efficiency.Finally,the seed yield was significantly reduced by 24.96% under enhanced UV-B radiation.