不同海拔高度矮嵩草的光合响应差异

Difference in photosynthetic response of Kobresia humilis along latitude gradients

高海拔地区具有强光辐射、低CO2分压和低温等环境特征。长期生长在高海拔地区的植物各自形成了其独特的适应特性。为了揭示矮嵩草(Kobresia humilis)对不同海拔的光合生理适应机制,使用Li-6400便携式光合作用测量系统观测了大阪山阴坡生长于3个不同海拔高度(3000 m、3400 m、3800 m)矮嵩草光响应和CO2响应曲线。结果显示,在测量温度下,矮嵩草的最大净光合速率和光合能力随海拔梯度升高而逐渐提高;高海拔地区生长的矮嵩草具有较高的羧化效率,而低海拔地区生长的矮嵩草具有较高的表观量子效率。高海拔地区生长的矮嵩草具较高的光饱和点,较低的CO2补偿点和饱和点,而不同海拔间的光呼吸速率无显著差异。研究结果表明,矮嵩草表现出对高海拔地区环境积极的适应方式。

Environments in high latitude area are characterized by intense radiation, low CO2 pressure and low temperature. Plants grown in such environment possess unique traits. To study the photosynthetic adaptive mechanisms of Kobresia humilis to high latitude environment, we measured light response and CO2 response curves of this plant that was grown in 3 different latitudes （3000 m, 3400 m, 3800 m） by using Li-6400 portable photosynthetic measurement system. The results showed that under setting temperature, the maximum photosynthetic rate and photosynthetic increased with latitude gradients; K. humilis lived in high latitude had higher carboxylation efficiency. K. humilis lived in low latitude, on the other hand, had higher apparent quantum yield. Plant light saturation point lived in high latitude was higher than that lived in low latitude, but they had lower CO2 compensation point and CO2 saturation point. The photorespiration differences of plants among latitude gradient were not significant. Based on those results, we concluded that K. humilis could be well adapted to the high latitude environment.