Studies On Carbohydrate Allocation In Tree Peony And Senescence Physiology In Flower Of Tree Peony

By measurement of net photosynthesis(Pn), chlorophyll fluorescence, soluble sugar content, respiration, MDA content, pigment content of flower, in Rou Fu Rong, a kind of tree peony. Relationship between carbohydrate allocation and photosynthesis in leaves in florescence and flower senescence period in tree peony were investigated in this paper. The main results are as follows:1. Before flower senescence period, net photosynthetic rate in leaves on branches without flower (NFL) was higher than that in leaves on branches with flower(FL).With senescing of flower, net photosynthetic rate of NFL decreased markedly, approaching net photosynthetic rate in FL. After flower senescence, net photosynthetic rate of NFL and FL changed in similar way.2. There were no obvious differences between Fv/Fm andΦPSⅡin NFL and FL. In general, the carboxylation efficiency (CE) exhibited a similar trends as the changes of the net photosynthetic rate. This indicated that lower CE might be a reason of lower net photosynthetic rate in the FL.3. Total soluble sugar content in the NFL was lower than that in the FL, and total soluble sugar content in the FL did not change after a whole night consumption. After florescence, the total soluble sugar content in the FL in the early morning was obviously lower than that on previous day afternoon. But the total soluble sugar content in the NFL in the early morning was always lower than that on previous day afternoon in florescence and flower senescence.4. Starch content in the NFL and the FL increased first and then decreased, the maximal content emerged in florescence period, and at this time, starch content in the NFL was a little higher than that in the FL.5. Starch content in roots decreased obviously, but soluble sugar content changed little during florescence period. Changes of starch content and soluble sugar content in branches was similar to that in roots, however, the...