生态因子对地被石竹光合作用的影响

采用Li-6400型光合作用系统,对不同季节地被石竹的光合日变化进行研究,通过相关分析和通径分析,得出光合速率与生态因子间的关系,并综合曲线拟合和多元逐步回归分析方法对净光合速率(Pn)与影响因子建立相应的优化模型方程.结果表明:(1)地被石竹叶片Pn的日变化在春季和秋季呈单峰曲线型;夏季表现为双峰曲线型,具有典型的光合"午睡"现象.(2)春季,蒸腾速率和气温是直接影响地被石竹叶片Pn的主要因子;夏季,空气相对湿度、胞间CO2浓度和气温是直接影响Pn的主要因子;秋季,胞间CO2浓度和蒸腾速率是直接影响Pn的主要因子.(3)地被石竹光补偿点约为56.94μmol.m-2.s-1,光饱和点约为800μmol.m-2.s-1,补偿点、饱和点均较高,属于喜光植物.

Effects of ecological factors on photosynthesis of Dianthus plumarius

Using Li-6400 photosynthesis system,photosynthesis diurnal variation of Dianthus plumarius during different seasons was studied.By the correlation analysis and path coefficient analysis,this paper assessed the relationship between net photosynthetic rate(Pn) and ecological factors and constructed related optimization model with curve fitting and multiple stepwise regression.The results were as follows:(1) The diurnal variation of Pn had a single curve in spring and autumn and the double-peak curve in summer,which had obvious midday photosynthetic depression.(2) Transpiration rate and temperature were the most important direct factors to influence the changes of Pn in spring.The leading factors directly affecting Pn were relative humidity,intercellular CO2 concentration and temperature in summer.In autumn,intercellular CO2 concentration and transpiration rate directly affected Pn.(3) The light compensation point of D.plumarius was about 56.94 μmol·m-2·s-1 and the light saturation point was around 800 μmol·m-2·s-1,so D.plumarius is a heliophyte.