红厚壳的光合水分生理生态特性

Characteristics of Photosynthesis and Water Physio-ecology of Calophyllum inophyllum Linn.

研究了海南岛低山丘陵区红厚壳(Calophyllum inophyllum Linn.)在30℃温度条件下,不同光合有效辐射(PAR)强度及不同CO2摩尔分数(Ca)范围内叶片光合及水分生理生态参数的变化特征。结果表明:(1)400μmol/molCO2摩尔分数条件下,红厚壳叶片净光合速率(Pn)与PAR之间的回归方程:Pn=-1.3×10-6PAR2+4.89×10-3PAR-0.40902,相关系数(r)可达0.9214;光饱和点、补偿点及表观量子效率分别为1880.77μmol/(m2.s),85.59μmol/(m2.s),0.01644mol/mol;叶片蒸腾速率(Tr)与PAR间回归方程:Tr=-6.7098×10-8PAR2+2.8×10-4PAR+0.29612,相关系数r=0.8998;叶片水分利用率(WUE)与PAR间回归方程:WUE=-3×10-6PAR2+0.01093PAR-1.71097,二次回归关系较弱,相关系数为0.7601(n=39);(2)PAR为1000μmol.m-2.s-1PAR条件下,Pn与CO2之间回归方程Pn=-5.73×10-6Ca2+0.0161Ca-0.9765,相关系数r为0.9936,CO2饱和点、补偿点及羧化效率分别为1404.89μmol/mol,62.01μmol/mol,0.01598mol/mol;叶片蒸腾速率与Ca间回归方程:Tr=1.1804e-0.0009Ca,相关系数r为0.9803,水分利用率随CO2的增加呈直线上升,二者正相关明显WUE=2.33×10-2Ca-3.116,相关系数r为0.9821(n=36)。

The changes of leaf p botosynthesis and water physio-ecology parameters of Calophyllum inophyllum Linn on the low hill land in Hainan Island were observed under various intensities of photosynthesis active radiation （PAR） and different CO2 concentrations （Ca） at the temperature of 30 ℃. Regression equations were established based on the observations. Under 400 μmol/（mol·s） Ca, the regression equation between net photosynthesis rate （Pn） and PAR is Pn=-1.3×10^-6 PAR^2＋4.89×10^-3 PA R-0.409 02 with a regression coefficient（r） 0.921 4,and the critical points for light saturation, light compensation, apparent quantum yield（AQY） are 1 880.77 μmol/（m^2·s）, 85.59 μmol/（m^2·s） and 0.016 44 mol/mol, respectively. The regression equation between transpiration （Tr） and PAR is Tr=-6.709 8×10^-8 PAR^2＋2.8×10^-4PAR＋0.296 12 with r=0.899 8. The relationship between water utilization efficiency （WUE） and PAR showed parabola trends with r=0.760 1 （n=39）. Under 1 000 μmol/（m^2·s） PAR, the regression equation between Pn and Ca is Pn=-5.73×10^-6Ca^2＋0.016 1Ca-0.976 5 and r is close to 1.0, and the CO2 saturation point, compensation point and carboxylation efficiency are 1 404.89 μmol/mol, 62.01 μmol/mol and 0.015 98 mol/mol, respectively. The Tr showed negatively exponential down trend with increase in Ca： Tr=1.180 4^ e-00009Ca,and r=0.980 3.The WUE showed linear up trend with an increase in Ca,and the coefficient r is close to 1.0（n=36）.