Li Wei D, Duan Wei, Fan Pei G, Yan Shu T, Li Shao H
Institute of Botany, The Chinese Academy of Sciences, 100093 Beijing, P.R. China.
Tree Physiol. 2007 Sep;27(9):1307-18. doi: 10.1093/treephys/27.9.1307.
Fruits were removed (-fruit) or retained (+fruit) on limbs of 'Yanfengyihao' peach (Prunus persica (L.) Batch) trees. In addition to the -fruit and +fruit treatments, leaves on 1-year-old fruit-bearing shoots of 'Bayuecui' peach trees were covered with bags for varying periods of time. Net photosynthetic rate (P(n)), stomatal conductance and transpiration rate around midday significantly decreased in the -fruit treatment and significantly increased in bagged leaves after removal of the bags compared with values in the +fruit treatment. Leaf temperature (T(l)) was higher in the -fruit treatment than in the +fruit treatment, and P(n) decreased in the -fruit treatment, especially when T(l) exceeded 38 and 36 degrees C in 'Yanfengyihao' and 'Bayuecui', respectively. Fruit removal resulted in a significant accumulation of sorbitol and starch in leaves, but it did not decrease activities of enzymes involved in carbon metabolism in leaves of 'Yanfengyihao'. In contrast, activities of aldose-6-phosphate reductase and ADP-glucose pyrophosphorylase sometimes increased in leaves in the -fruit treatment. In 'Bayuecui', fruit removal significantly decreased maximal fluorescence and photochemical efficiency and increased minimal fluorescence around midday compared with values in the +fruit and bag treatments. The photosynthetic apparatus of peach may be damaged when T(l) exceeds a critical temperature under conditions of decreased sink demand. Decreased stomatal aperture and increased T(l) may regulate photosynthesis by affecting electron transport.
在‘燕丰一号’桃树（Prunus persica (L.) Batch）的枝条上去除果实（-果实）或保留果实（+果实）。除了-果实和+果实处理外，对‘八月脆’桃树一年生结果新梢上的叶片进行不同时长的套袋处理。与+果实处理相比，-果实处理中午前后的净光合速率（P(n)）、气孔导度和蒸腾速率显著降低，套袋叶片去袋后这些指标显著升高。-果实处理的叶片温度（T(l)）高于+果实处理，且-果实处理中P(n)降低，尤其是当‘燕丰一号’和‘八月脆’的T(l)分别超过38℃和36℃时。去除果实导致叶片中山梨醇和淀粉显著积累，但并未降低‘燕丰一号’叶片中参与碳代谢的酶的活性。相反，-果实处理中醛糖-6-磷酸还原酶和ADP-葡萄糖焦磷酸化酶的活性有时会升高。与+果实和套袋处理相比，‘八月脆’去除果实显著降低了中午前后的最大荧光和光化学效率，并增加了最小荧光。在库需求降低的条件下，当T(l)超过临界温度时，桃树的光合机构可能会受损。气孔孔径减小和T(l)升高可能通过影响电子传递来调节光合作用。
