紫楠实生幼苗的光合生理特性

Study on Photosynthetic Physiology Characteristics of Young Phoebe sheareri Seedling

为探明紫楠幼苗的光合特性,从而为紫楠的育苗技术提供一定的理论依据,以紫楠播种苗为试验材料,对其光合速率、蒸腾速率日变化和光响应曲线、CO2响应曲线进行了测定。结果表明:紫楠幼苗的净光合速率日变化呈双峰曲线,蒸腾速率日变化呈单峰曲线,存在"午休"现象,日平均净光合速率、蒸腾速率分别为3.30μmol/(m2·s)、1.94mmol/(m2·s);紫楠的日平均光能利用率仅为0.11%。紫楠的表观量子效率较高,达0.047,其光饱和点、光补偿点分别为1 140.82μmol/(m2·s)和13.495μmol/(m2·s);CO2补偿点和CO2饱和点分别为73.318μmol/(m2·s)和1 571.202μmol/(m2·s)。综合各参数分析,紫楠幼苗具有耐阴性,育苗时宜选择阴湿的地方有利于苗木更好地生长。

In order to make clear the photosynthetic characteristics of P.sheareri seedling,which can provide certain theoretical basis for the seedling technique of P.sheareri.The P.sheareri seedling by sowing as experiment materials,the photosynthetic characteristics,transpiration characteristics and photosynthetic parameters were determined. The results showed that the diurnal change of net photosynthetic rate of P.e sheareri seedling was bimodal curve and the diurnal change of transpiration rate was double-peak curve.Moreover,midday depression existed.The daily average net photosynthetic rate was 3.30μmol/(m2·s).The average solar utilization efficiency(SUE)of P.sheareri was merely 0.11%,and the average water utilization efficiency(WUE)of it was 1.94μmol/μmol.The apparent quantum yield(AQY)of P.sheareri reached 0.047,which was relatively high.The light saturation point(LSP)and the light compensation point(LCP)was 1 140.82μmol/(m2·s),13.495μmol/(m2.s)respectively.The CO2compensation point and CO2saturation point was 73.318μmol/(m2·s),1 571.202μmol/(m2·s)respectively.According to the parameters above,the study reveals that the P.sheareri seedling is shade tolerant.Hence,it is beneficial for the better growth of P.sheareri seedling to choose the shady and damp places.