| 摘要: |
| 采用Li-6400便携式光合测定系统(Li-Cor Inc., USA) 对常绿灌木紫花含笑和常绿乔木苦梓含笑的光合生理特性进行了测定。结果表明: (1) 两种含笑叶片的光响应曲线符合非直角双曲线模型，表观光量子效率接近，但灌木紫花含笑的光饱和点、光补偿点、最大净光合速率、暗呼吸速率均比乔木苦梓含笑低。 (2)光照强度对两种含笑的气孔行为、蒸腾速率和水分利用率的影响效果近似，光照强度诱导气孔导度变大，蒸腾速率加强。当达到光饱和后，随着光强的增强，净光合速率增加缓慢，气孔导度和蒸腾速率持续增大，水分利用率下降。 |
| 关键词: 光响应曲线 气孔导度 蒸腾速率 水分利用率 |
| DOI： |
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| Study on photosynthetic characterization of Michelia crassipes and Michelia balansae |
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Ma Xiaoying
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| Abstract: |
| The photosynthetic characteristics of a shcrub, Michelia crassipes, and a tree, Michelia balansae, were measured in the field with Li-6400 Portable Photosynthesis System (Li-Cor Inc. , USA). The results were: (1) The response of photosynthesis to photon flux density fitted well with the non-rectangular hyperbola model. The apparent quantum yield of two species were close, but the light saturation point and compensation point, the maximum net photosynthetic rate, the dark respiration rate of M. crassipes were lower than those of M. balansae. (2) The response of stomatal conductance, transpiration rates and water use efficiency of the two species were similar. The photon flux density induced the increament of stomatal conductance and transpiration rate. When reaching to the light saturation point, the net photosynthetic rate leveled off, but the stomatal conductance and the transpiration rate kept increasing, resulting in the decrease of water use efficiency. |
| Key words: Light response curve, stomatal conductance , transpiration rate , water use efficiency |
