粗壮女贞光合日变化的初步研究

Preliminary Study on Photosynthetic Diurnal Variation of Ligustrum robustum

为了对粗壮女贞的高产优质栽培提供理论依据,在无风的天气条件下,用LI-6400便携式光合仪测定了粗壮女贞的光合作用日变化特性,分析净光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）与叶表面蒸汽压亏缺（Vpdl）等光合指标。结果表明：粗壮女贞的Pn,Tr,Gs,Vpdlde的日变化均为典型的单峰曲线,未出现午休现象;Pn峰值约出现在16：00时,为10.21μmolCO2/（m^2·s）,在12：00-14：00时,Pn随光照强度增强大幅度上升,14：00-16：00时达到最高峰,之后为减少蒸腾作用,气孔关闭,Pn下降;粗壮女贞的Tr,Gs,Vpdl与Pn的日变化规律一致,也呈单峰曲线。

The Pn,Tr,Gs and Vpdl indexes of Ligustrum Robustum leaves was determined by LI-6400 photosyntometer to study its photosynthetic diurnal variation and to provide theoretical basis for its cultivation with high yield and quality.The results showed that the photosynthetic diurnal variation was a single-peak curve without ＂midday rest＂ phenomenon,the Pn greatly increased with the increase of light intensity during 12：00～14：00 and reached the peak 10.21μmol CO2/（m^2·s） at 16：00,and then declined because of stomatal closing for reducing transpiration,and the diurnal variation regulation of Tr,Gs and Vpdl was the same as Pn.