低温弱光对番茄叶片光合作用和叶绿素荧光参数的影响

Effects of Chilling under Low Light on Photosynthesis and Chlorophyll Fluorescence Characteristic in Tomato Leaves

低温弱光 (温度 5、 10℃和光强 60 μmol·m- 2 ·s- 1)导致番茄植株生长停滞 ,叶绿素含量、净光合速率、气孔导度和胞间CO2 浓度下降 ,但经 5℃处理的植株下位叶的胞间CO2 浓度与对照无显著差异。经 10℃处理的植株在正常生长条件下净光合速率能迅速恢复到对照水平 ,而 5℃处理的植株则恢复缓慢。 10℃处理对光系统Ⅱ的光化学效率Fv/Fm并无显著影响 ,光系统Ⅱ光合电子传递量子效率ΦPSⅡ在低温处理后期略有下降并能迅速恢复 ;5℃处理下Fv/Fm和ΦPSⅡ均随处理时间的延长而降低 ,且需恢复

Exposure of tomato plants to low temperature(10℃ and 5℃)under low light(60μmol·m -2 ·s -1 )resulted in an completely inhibition of plant growth and decreased chlorophyll content,net photosynthetic rate(Pn),stomatal conductance(Gs)and intracellular CO 2(Ci)concentration except Ci for the lower leaves during chilling at 5℃.During the recovery,Pn for 10℃ treatment arose to a value similar to control,but Pn for 5℃ treatment did not.Chilling at 10℃ did not affect Fv/Fm,but slightly decreased ΦPSⅡ although it recovered soon after chilling stress.However,chilling at 5℃ considerably decreased Fv/Fm and ΦPSⅡ,and both recovered slowly after chilling stress.