4个油桐品种光合特性的日变化研究

利用Li-6400便携式光合测定系统，测定了4个油桐品种光合指标的日变化。结果表明：⑴‘葡萄桐’、‘小米桐’、‘对年桐’的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)日变化均呈单峰曲线，‘大米桐’的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)日变化呈双峰曲线；⑵4个品种的胞间CO2浓度(Ci)日变化呈不规则的“V”字型；⑶4个品种净光合速率日变化平均值大小排序为:‘葡萄桐’>‘小米桐’>‘对年桐’>‘大米桐’；⑷影响油桐净光合速率值的主要生态生理指标大小依次为：蒸腾速率>胞间CO2浓度>光合有效辐射>气孔导度。

Daily changes of photosynthetic characteristics of four cultivars of tung tree (Vernicia fordii)

The photosynthetic characteristics of four cultivars of tung tree were measured with lico-6400 photosynthetic instrument.The results showed that:⑴ Net photosynthetic rate , stomatal conductance and transpiration rate of the cultivas‘Putaotong’,‘Xiaomitong’and ‘Duiniantong’were changed as single peak curve,while ‘Damitong’was changed as bimodal peak curve;(2) Intercellular CO2 of four cultivars of tung tree concentration appeared to vary in a V-shaped curve; (3)The order in daily chang of average net photosynthetic rate of them was taken as‘Putaotong’>‘Xiaomitong’>‘Duiniantong’>‘Damitong’; (4) The impact order that main ecological physiological of net photosynthetic value of tung tree was transpiration rate>intercellular CO2 concentration>PAR>stomatal conductance.