柑桔越冬后叶片的光合动态

试验用便携式 CO_2红外分析仪对杭州地区温州蜜柑越冬后叶片光合动态进行了测定.结果表明越冬后叶片的净光合速率总趋势是上升,即有越冬后叶片的光合恢复现象.净光合以秋叶最大,夏叶次之,春叶最低.净光合和气温的变化动态有着明显的关系.在越冬后叶片的光合恢复过程中,叶片叶绿素含量提高,表观量子产量上升,而羧化效率几乎不变,表明越冬后叶片光合潜力的恢复主要取决于叶片对光能利用的改善.

Changes in Leaf Photosynthesis of Citrus After Winter

The experiment was carried out using a portable CO_2 Infra—gas—analyser to measureleaf photosynthetic rates of Citrus unshiu after winter in Hangzhou.The photosynthetic ratesof three leaf types(spring,summer and autumn leaf of last year)of trees tended to increase,a phenomena of the recovery of leaf photosynthesis after winter.But the levels of photosyn-thetic rate were different with three leaf types,being highest in autumn leaf,lowest in springleaf and intermediate in summer leaf.During the recovery of leaf photosynthesis the fluctua-tion of leaf photosynthetic rates was obviously related to that of air temperatures.Further-more,the recovery of photosynthesis was concurrent with the going—up of chlorophyll con-tent in the leaf,and consequently an evident increase in leaf apparent quantum yield,thoughthe carboxylstion efficiency kept almost constant.The results presented show that the recov-ery of leaf photosynthetic capacity of citrus after winter was closely dependent on the regainof leaf capacity to use light energy.