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作 者 ：刁俊明;孙卿;陈桂珠*

期 刊 ：植物研究 2010年 30卷 4期 页码：416-423

关键词：桐花树；淡水驯化；净光合速率；气孔导度；蒸腾速率；

Keywords:Aegiceras comiculatum, fresh water adaptation, net photosynthetic rate, stomatal conductance, transpiration rate,

摘 要 ：以实验地全光照条件下淡水和人工海水培养种植的桐花树（Aegiceras corniculatum）幼苗为材料，采用Li6400光合测定仪对不同月份桐花树幼苗的光合生理生态特性日动态进行测定，研究了桐花树的光合生理生态特性。结果表明：在7、10月份桐花树的净光合速率日变化呈双峰型，均出现“光合午休”现象。在7月份人工海水组和淡水组的最大净光合速率（P_max）分别为9.97和11.95 μmol·m^-2·s^-1；而10月份的P_max分别为12.2和12.9 μmol·m^-2·s^-1。而且淡水驯化下，桐花树的净光合速率较人工海水组高。由光响应曲线可知，桐花树人工海水组的最大净光合速率（P_max）、光饱和点（LSP）、光补偿点（LCP）和表观量子效率（AQY）分别为7 μmol·m^-2·s^-1，1 477 μmol·m^-2·s^-1，30 μmol·m^-2·s^-1，0.031 3；而淡水组为8.69 μmol·m^-2·s^-1，980 μmol·m^-2·s^-1，40 μmol·m^-2·s^-1，0.011。在所测的生理生态因子中，光合有效辐射和气孔导度是影响桐花树光合作用最为强烈的因子，与桐花树的净光合速率和蒸腾速率均有极显著的相关关系（p<0.01）。试验说明淡水驯化的桐花树对光强的利用范围变窄，但有较高的净光合速率，表明桐花树对淡水环境具有较强的适应性。

Abstract:The photosynthetic characteristics of Aegiceras comiculatum seedlings respectively cultivated in fresh water and artificial sea water were measured in different months with Li-6400 photosynthetic system. Results showed that in July and October, the net photosynthetic rate of A.comiculatum seedlings demonstrated a “double peak pattern” of daily change along with the phenomenon of noon break. In July, the maxium net photosynthetic rates（P_max）of the artificial sea water group and the fresh water group were respectivley 9.97 and 11.95 μmol·m^-2·s^-1；and in October the P_max of the two groups were respectively 12.2 and 12.9 μmol·m^-2·s^-1. After fresh water adaptation, A.comiculatum demonstrated higher net photosynthetic rates than those cultivated in artificial sea water. From the light response curves, the maxium net photosynthetic rate（P_max）, light saturated point（LSP）, light compensated point（LCP）and apparent quantum yield（AQY） were obtained, which were respectively 7 μmol·m^-2·s^-1，1 477 μmol·m^-2·s^-1，30 μmol·m^-2·s^-1，0.031 3 for the artificial sea water group；and respectively 8.69 μmol·m^-2·s^-1，980 μmol·m^-2·s^-1，40 μmol·m^-2·s^-1，0.011 for the fresh water group. Of the physiological and ecological factors that have been measured, the photosynthetic active radiation and stomatal conductance had the largest effects on the photosynthesis of A.comiculatum, which exhibited highly significant correlationships with net photosynthetic rate and transpiration rate. After fresh water adaptation, A.comiculatum demonstrated a narrower range of utilizable light intensity, but higher net photosynthetic rate, which indicated that A.comiculatum had a strong adaptability to fresh water environment.

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