Three days old cucumber (Cucumis sativus L.) was grown in a factorial design under two levels of water condition (well watered and drought) and two supplemental levels of ultraviolet\|B(280—320 nm) irradiance(0, ...Three days old cucumber (Cucumis sativus L.) was grown in a factorial design under two levels of water condition (well watered and drought) and two supplemental levels of ultraviolet\|B(280—320 nm) irradiance(0, 0\^24, 0\^42 W/m\+2) for 30 days. Plants were grown in a greenhouse under visible light with 400 μmol/(m\+2.s), day\|night temperature 32/20℃ and relative humidity 70±10%. The combination of UV\|B radiation and water stress resulted in the decrease in plant height, leaf area ratio and relative growth rate, and increase in specific leaf mass and net assimilation rate. There was almost no effect of ultraviolet\|B radiation on the contents of chlorophyll a and b under water stress. However, interactive effects of ultraviolet\|B radiation and water conditions on the content of anthocyanin were much great. UV\|B irradiance with water stress also caused a reduction in net photosynthesis, apparent quantum efficiency, gas exchange and stomatal resistance, and an increase in evaporation.展开更多
文摘Three days old cucumber (Cucumis sativus L.) was grown in a factorial design under two levels of water condition (well watered and drought) and two supplemental levels of ultraviolet\|B(280—320 nm) irradiance(0, 0\^24, 0\^42 W/m\+2) for 30 days. Plants were grown in a greenhouse under visible light with 400 μmol/(m\+2.s), day\|night temperature 32/20℃ and relative humidity 70±10%. The combination of UV\|B radiation and water stress resulted in the decrease in plant height, leaf area ratio and relative growth rate, and increase in specific leaf mass and net assimilation rate. There was almost no effect of ultraviolet\|B radiation on the contents of chlorophyll a and b under water stress. However, interactive effects of ultraviolet\|B radiation and water conditions on the content of anthocyanin were much great. UV\|B irradiance with water stress also caused a reduction in net photosynthesis, apparent quantum efficiency, gas exchange and stomatal resistance, and an increase in evaporation.
