干旱区3种彩叶植物的光合特性

Photosynthetic Characteristics of Purple-leaf Plants in Drought Region

以3 a生紫叶李(Prunus cerasifera Ehrhart f.atropurpureaJacq)、紫叶矮樱(Prunus×cistena Pis-sardii)、紫叶桃(Prunus persicacv.atropurpurea)为试材,研究3种彩叶植物的光合作用基本生理特征和规律。结果表明,紫叶桃、紫叶李和紫叶矮樱的光补偿点分别为12、24和92μmol.m-2.s-1;光饱和点分别为1 044、688和1 196μmol.m-2.s-1;表明紫叶矮樱较为喜阳,在园林绿化配置时应处于群落的上层。紫叶李与紫叶矮樱有明显的光合"午休"现象,主要是由气孔导度下降引起的,紫叶桃是由非气孔因子限制的。3种植物的蒸腾速率都为午后高峰型。环境因子地表温度日变化大于地下温度日变化,地表湿度与地表温度日变化成反比。

The photosynthetic characteristics of three purple-leaf plants were studied in this research,the results would provide scientific guidance for configuring colorful plants in plant landscaping.The portable photosynthetic system LI-6400（LI-COR company,U.S） was used to measure daily changes and light response curves of three years old purple-leaf lee（Prunus cerasifera Ehrhart f.atropurpurea Jacq）,purple-leaf dwarf cherry（Prunus×cistena Pissardii） and purple-leaf peach（Prunus persica cv.atropurpurea）.The light compensation point of purple-leaf peach,lee and dwarf cherry were 12,24,92 μmol·m-2·s-1,respectively;light saturation point were 1 044,688,1 196 μmol·m-2·s-1,respectively.The purple-leaf dwarf cherry showed some characters of heliophilous plants,so,in landscape configuration they should be placed in a upper level of a plants community.The purple-leaf lee and purple-leaf dwarf cherry have a clear photosynthetic ＂midday depression＂ around noon,which is mainly caused by the decline of stomatal conductance,while purple leaf peach is limited by non-stomatal factors.The transpiration rates of three tree species belong to the afternoon peak type.Diurnal temperature variation of the ground surface is greater than it in the ground,and the surface humidity variation is inversely proportional to the diurnal ground surface temperature change.