山茱萸幼树光合及水分生理生态特性

Characteristics of Photosynthesis and Water Physio-ecology of Young Macrocarpium officinalis

采用Li 6400光合分析仪,研究了太行山退耕还林地山茱萸幼林在20℃温度条件下,不同光合有效辐射(PAR)强度及不同CO2浓度内的叶片光合作用及水分生理生态参数的变化特征,结果表明:(1)400μmol·mol-1CO2浓度条件下,山茱萸幼树叶片净光合速率(Pn)与PAR之间的回归方程:Pn=-8×10-6PAR2+0 0222PAR+1 9509,相关系数可达0 9524(n=33);光饱和点、补偿点及表观量子效率分别为1387 50μmol·m-2·s-1、17 4μmol·m-2·s-1、0 0663mol·mol-1;叶片蒸腾速率(Tr)与PAR间回归方程:Tr=0 0013PAR+5 637,线性相关系数达0 9830;叶片水分利用率(WUE)随PAR增强呈明显的抛物线状变化趋势,二者相关系数可达0 9222(n=33);(2)1200μmol·m-2·s-1PAR条件下,Pn与[CO2]之间回归方程Pn=-2×10-5[CO2]2+0 0502[CO2]-2 9656,相关系数接近于1 0(n=30),CO2饱和点、补偿点及羧化效率分别为1255μmol·mol-1、60 5μmol·mol-1、0 0406;Tr随[CO2]的增加呈直线下降趋势,但二者关系并不明显,WUE与[CO2]之间回归方程为:WUE=-4×10-6[CO2]2+0 0084[CO2]-5 5052。相关系数接近于1 0(n=30)。

On the conditions of 20 ℃,the various intensities of photosynthesis active radiation (PAR) and different CO_2 concentrations(),the characteristics of leaf photosynthesis and water physio-ecology of young Macrocarpium officinalis on the convering tree land from farming were studied. The results showed that:(1)under 400 μmol·mol^(-1)·s^(-1),the regression equation between net photosynthesis rate (P_n) and PAR is P_n=-8×10^(-6)PAR^2+0.022 2PAR+1.950 9 with a regression coefficient(r)=0.952 4(n=33); the critical points of light saturation and light compensation,apparent quantum yield (AQY) is 1 387.5 μmol·m^(-2)·s^(-1) and 17.4 μmol·m^(-2)·s^(-1),0.066 3 mol·mol^(-1) respectively.The regressive equation between transpiration (Tr) and PAR is Tr=0.001 3 PAR+5.637 with r= 0.983 0(n=33).The relationship between water utilization efficiency (WUE) and PAR showed parachute trends with r=0.922 2(n=33).(2)At 1 200 μmol·m^(-2)·s^(-1) PAR,the regressive equation between P_n and is P_n=-2×10^(-5)~2+0.050 2-2.965 6 and r is close to 1.0(n=33).CO_2 saturation point,compensation point and carboxylation efficiency is 1 255 μmol·m^(-2)·s^(-1),60.5 μmol·m^(-2)·s^(-1),and 0.040 6 respectively;Tr showed linely down trend with decreasing,but there was no significant correlation between them,the regressive equation between WUE and is WUE=-4×10^(-6)~2+0.008 4-5.505 2 and r is close to 1.0(n=30).