不同生境条件下黄芩光合日变化与环境因子的关系

Relationship between diurnal changes of photosynthesis of Scutellaria baicalensis and environmental factors in different habitats

在黄芩盛花期,测临江、长春、洮南3个不同生境条件下黄芩Pn及环境因子的日变化,对测得数据进行统计分析,探讨黄芩Pn与环境因子的关系,为吉林省黄芩规范化种植提供理论依据。结果表明,3个不同生境黄芩Pn日变化均呈不明显双峰曲线,有轻微光合"午休"现象,黄芩Pn中午降低均为气孔限制;三地黄芩Pn与PAR均呈极显著正相关(p<0.01),长春黄芩Pn与Ca呈极显著正相关(p<0.01),洮南黄芩Pn与RH呈显著正相关(p<0.05);3个不同生境环境因子对Pn的直接作用由大到小分别为临江PAR>Ca>Ta>RH>TL,长春Ta>RH>PAR>Ca>TL,洮南PAR>RH>TL>Ca>Ta;低的空气湿度是产生光合"午休"现象的重要生态因子;临江高温高湿、长春大气CO2浓度低、洮南相对湿度低是影响各生境黄芩Pn的主要环境因子;对黄芩Pn影响是PAR、Ta、RH、Ca相互影响综合作用的结果,在不同生境下,发挥主导作用的环境因子不同。

During the flowering period, the diurnal changes three different habitats （Linjiang, Changchun, Taonan） were of Pn of Scutellaria baicalensis and environmental factors in measured, and the obtained data were analyzed to explore the diurnal changes of Pn and its relationship with environmental factors from three different ecological zones. The conclusion will provide the theoretical basis of physiology and ecology of photosynthesis for scale field cultivation of S. baicalensis in Jilin province. The results indicated that the diurnal changes of Pn of S. baicalensis in three different habitats showed a typical double-peak curve with a slight ＂midday depression of photosynthesis＂, and the Pn reduction at noon originated from the co-effects of stomata factor. There was a significant （p 〈 0.01 ） positive relationship between the Pn and PAR in the three zones. The positive relationship was significant （p 〈 0. 01 ） between the Ca and the Pn in Changchun, and significant （p 〈0.05） between the relative humidity and the Pn in Taonan. The direct impact of environmental factors to Pn in three different habitats was the order of PAR 〉 Ca 〉 Ta 〉 Rtt 〉 TL in Linjiang, Ta 〉 RH 〉 PAR 〉 Ca 〉 TL in Changchun, PAR 〉 RH 〉 TL 〉 Ca 〉 Ta in Taonan. Low air humidity was an important ecological factor in determining the ＂midday depression of photosynthesis＂. High temperature and humidity in Linjiang, low CO2 concentration in Changchun, and low relative humidity in Taonan were the main environmental factors influencing the net photosynthetic rate of S. baicalensis, in which was affected by the integration and interactions of PAR, Ta, RH, and Ca. The dominant factor for the net photosynthetic rate of S. baicalensis was different in different habitats.