金桔秋季光合特性初步研究

Preliminary Study on Photosynthetic Characteristics of Citrus microcarpa in Autumn

采用Li-6400型便携式光合测定系统对多年生金桔的光合特性进行研究。结果表明,金桔净光合速率日变化呈双峰曲线,存在光合"午休"现象,最高峰出现在11:00左右,次峰出现在14:00,日最大净光合速率为3.4467μmol/m2·s。净光合速率与蒸腾速率、气孔导度之间呈正相关,与胞间CO2浓度呈负相关;在400μmol/molCO2浓度下,光补偿点为67μmol/m2·s,光饱和点为672μmol/m2·s。金桔的光合特性表现为典型的阳性耐荫植物,对光照的适应性较强。

The photosynthetic characteristics of Citrus microcarpa were determined with the Li-6400 Photosynthetic system. The results showed that the diurnal variation of net photosynthetic rate （Pn） in Citrus rnicrocarpa was a double-peak curve and there also exists a clear depression at noon. The first peak occurred at 11：00, the second one at 14：00. The maximum of net photosynthetic rate （Pmax） was 3.4467 umol/m^2.s. Correlation analysis showed that there were positive relationship between Pn and transpiration rate （Tr） and stomatal conductance （Gs）, and negative relationship between Pn and internal CO2 concentration （Ci）. Under the concentration of CO2 400 pmol/mol, the light compensation point （LCP） of Citrus microcarpa was 67 pmol/m2-s, and light saturation point （LSP） was 672 umol/m〈s. In sum, Citrus microcarpa is a typical masculine and shade-resistant plant which has strong adaptability to the circumstance.