库-源调节对沙糖桔源叶光合特性的影响

Effects of source-sink manipulation on leaf photosynthetic Characteristics in Shatangju tangerine

以沙糖桔为材料,在果实膨大期通过去果处理降低库力,同时设留果作对照,环剥1年生春梢结果枝和保留相同数量叶片严格控制光合产物的交流,并对源叶净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)等叶片光合特性进行比较研究,探讨去果调节库-源关系后对沙糖桔叶片光合特性的影响。结果表明:去果减库显著降低沙糖桔叶片的Pn、Gs和Tr,而对饱间CO2浓度(Ci)、气孔限制值(Ls)和水分利用率(WUE)影响不大;库-源关系的改变不影响沙糖桔叶片Pn的日变化曲线,仍然表现为典型的"双峰"曲线,首峰、次峰分别在上午8:00及下午14:00时出现,且均无明显光合"午休"现象。

In order to study the effects of altered source-sink correlation on leaf photosynthetic characteristics at fruit fast development stages in Shatangju tangerine, fruit thinning and retaining fruit were carried out on one-year-old shoot, and through preventing exportation of the assimilates to the non experimental parts of the tree by girdling one-year-old shoot and keeping the sane leaves between fruit thinning and retaining fruit, and the photosynthetic characteristic was analyzed. The results showed that： Fruit thinning significantly decreased net photosynthetic rate （Pn）, stomatal conductance （Gs） and transpiration rate（Tr）, while no significant different of substomatal CO2 （Ci） ,Ls and WUE. The alter of source-sink correlation did not impact the curve of the diurnal change in the Pn , they were all showed a typical bimodal curve, the first and the second peak occurredat 8：00 and 14：00 respectively, and no ＂midday depression phenomenon of photosynthesis＂ occurred .