牡丹开花前后碳水化合物的分配与光合速率的关系

Relationship Between Carbohydrate Allocation and Photosynthesis During Florescence and Flower Senescence Period in Tree Peony

以牡丹(Paeonia suffruticosa)品种‘肉芙蓉’为材料,研究其开花过程中碳水化合物的分配及其对有花枝上叶片(FL)与无花枝上叶片(NFL)净光合速率(Pn)的影响。结果表明:在花衰败前,有花枝Pn明显低于无花枝,但可溶性糖含量却高于无花枝。与前一天17时相比,经过一夜消耗后,早晨8时有花枝可溶性糖含量没有显著差别,而无花枝的则较低,说明除光合作用外,还有其他途径为有花枝提供可溶性糖。花衰败后,两种枝叶Pn和可溶性糖含量的差异逐渐消失。与花衰败前不同,经过一夜消耗后,早晨8时两种枝叶的可溶性糖含量比前一天17时都降低,表明为有花枝提供可溶性糖的其他途径在花衰败后停止工作,推测这一途径极可能与花的生长发育有密切联系。

Gas exchange, chlorophyll fluorescence and bio-analysis were used to study the influence of carbohydrate allocation on net photosynthetic rate in leaves of tree peony （Paeonia suffruticosa ‘Rou Furong＇ ） branches with and without flower. The results showed that before flower senescence, the net photosynthetic rate in leaves on branches with flower （FL） was lower than that in leaves on branches without flower （NFL）. Whereas the total soluble sugar content was higher in the FL than that in the NFL. Compared with that at 17：00 on the previous day, after a night consumption, the total soluble sugar content in the NFL decreased obviously at 8：00 a.m. while that in the FL hardly changed. These results indicate that there were other sources to supply soluble sugar in FL besides photosynthesis during the florescence period. After flower senescence, differences in net photosynthetic rate and total soluble sugar content between the NFL and the FL disappeared gradually, and the total soluble sugar content in both the FL and the NFL was lower at 8- 00 a. m. than that at 17：00 on the previous day, which suggest that the other sources mentioned above did not work to supply carbohydrates to the leaves any more. It is speculated that this metabolic pathway might be correlated with flower growth.