银杏与珊瑚树光合及蒸腾特性研究

A Comparative Study on the Photosynthesis and Transpiration in Ginkgo Biloba and Viburnum odoratissimum

通过测定相同生境中银杏(Ginkgobiloba)与珊瑚树(Viburnumodoratissimum)的净光合速率、蒸腾速率、气孔导度等生理性指标及其叶绿素含量,研究了两种植物在栽培条件下的光合与蒸腾特性。结果表明:银杏的光补偿点(45μmolm-2s-1)和光饱和点(1236μmolm-2s-1)高于珊瑚树的光补偿点(31μmol·m-2·s-1)和光饱和点(1125μmol·m-2·s-1),前者的光合作用最适温度也高于后者。银杏和珊瑚树的净光合速率日变化都呈现中午降低型,其蒸腾速率日变化也均呈单峰曲线变化。两种植物的气孔导度在午间保持较低值,对光合作用有明显的限制作用。

The photosynthesis and transpiration of leaves of Ginkgo biloba and Viburnum odoratissimum which planted in the same environment were measured in this paper. The results showed that the light compensation point of photosynthesis of Ginkgo biloba was 45 μmol·m^(-2)·s^(-1) and the light saturation point was 1236 μmol·m^(-2)·s^(-1), while those of Viburnnum odoratissimum. were 31 μmol·m^(-2)·s^(-1) and 1125 μmol·m^(-2)·s^(-1) respectively. The suitable temperature of Ginkgo biloba for photosynthesis was higher than that of Viburnum odoratissimum.The diurnal change curves of net photosynthesis rate of the two trees were of the midday-depression type, and those of transpiration rate displayed a single-peak. The photosynthesis was restricted by the decrease in stomatal conductance at midday.