| 摘要: |
| 应用 Li—6400 便携式光合作用测定系统对鸦胆子 Brucea javanica 雌雄株净光合速率日变化和光合作用—光响应曲线进行了测定，以探讨不同性别树种的光合作用特性及主要影响因子。结果表明：（1）自然条件下，鸦胆子雌雄株叶片净光合速率（Pn）的日变化曲线呈单峰型，无光合“午休”现象，其峰值都出现在 12:00 时左右。鸦胆子雌株的日最大同化速率（15.2 μmol · m-2 · s-1）大于雄株（10.8 μmol · m-2 · s-1），但两者 Pn 日均值差异不显著。雄株的水分利用效率日均值显著大于雌株（P ＜ 0.05）。（2）通径分析表明，影响鸦胆子雌雄株叶片 Pn 的主要决策因子都为蒸腾速率（Tr）和光合有效辐射（PAR），而胞间 CO2 浓度（Ci）是影响鸦胆子雌株叶片 Pn 的主要限制因子。（3）最大净光合速率雌株（21.7 μmol · m-2 · s-1）显著大于雄株（14.6 μmol · m-2 · s-1）。鸦胆子雌雄株叶片的光补偿点（LCP）分别为 40.6 和 32.3 μmol · m-2 · s-1，显示了阳生植物的特性。雌雄株叶片表观量子效率（AQY）值在 0.040~0.070 之内，显示出较强的光能利用效率，尤其是对弱光的利用能力。研究认为，鸦胆子雌株果实的存在可能提高其光合作用，增加气孔开放度和减少叶片的呼吸消耗；雄株较强的水分利用效率及对弱光的利用能力，体现出其对不利环境条件的较强适应能力。 |
| 关键词: 鸦胆子 光合日变化 雌雄异株 通径分析 |
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| 基金项目:广东海洋大学校级重点课程培育项目（GDOU580420013），广东海洋大学创新实验项目项目（GDOU580520031）。 |
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| Study on the Characteristics of Photosynthesis Diurnal Variation and Influence Factors of Male and Female Brucea javanica |
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Chen Junliang, chen Jiaying, chen qianqian, xu fengling, lilinfeng
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Guangdong Ocean University
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| Abstract: |
| The photosynthetic characteristics of male and female Brucea javanica had been measured by Li-6400 photosynthetic measurement system to explore the photosynthetic characteristics and influence factors of different gender plants. The results showed that: (1) daily variation of net photosynthetic rate in leaves of male and female B. javanica presented a single-peak curve, no “midday depression” phenomenon occurred, and the peak values appeared at about 12:00 noon. The daily maximum assimilation rate 15.2 μmol · m-2 · s-1 of female plants was more than male plants 10.8 μmol · m-2 · s-1, but there are no significant differences between the female and male plants. The means of water use efficiency in male plants was significantly higher than the female (P<0.05). (2) By path analysis, transpiration rate (Tr) and photosynthetic active radiation (PAR) are the main decision factors which affecting the characteristic of net photosynthetic rate ( Pn ) for both female and female plant of B. javanica. However, intercellular CO2 concentration was the main limiting factors which affecting the Pn of female plant. (3)The maximum net photosynthetic rate（Pmax） 21.7 μmol · m-2 · s-1 of female plant was significantly higher than 14.6 μmol · m-2 · s-1 of female plant. The light compensation point (LCP) values of female and male plant was 40.6 and 32.3 μmol · m-2 · s-1, respectively, which showed the typical properties of sun plants. The leaf apparent quantum efficiency (AQY) value of male and female plant was within the range of 0.040 to 0.070 mol · mol-1, showing strong light energy use efficiency, especially for the use of weak light. The study suggests that the fruiting may improve the photosynthesis, increase stomatal openness and reduce respiration consumption of leaves in female plant. Moreover, high water use efficiency and strong weak light energy use efficiency in the leaves of
male plant indicated its better adaptive ability to adverse environmental conditions. |
| Key words: Brucea javanica diurnal course of photosynthesis dioecious plants path analysis |
