不同光强对结果期草莓光合特性的影响

Influences of Different Light Intensities on the Photosynthetic Characteristics of Strawberry in Fruiting Stage

[目的]探索草莓光合特性的生理机制,为草莓的育苗和露地栽培提供理论指导。[方法]以草莓品种达赛莱克特为材料,在-1.28、-3.58-、5.56 MPa 3个叶片水势下研究不同光照强度对结果期草莓光合作用的影响。[结果]光照强度对结果期草莓的光合速率具有显著影响,光合速率在光照强度1200～1500μmol/（m^2·s）之间出现峰值。叶片水势越高,光照强度对光合速率的影响越明显。随着光照强度的增加,叶片气孔导度下降,水势较低的叶片气孔导度下降的趋势更明显。不同水势叶片的胞间二氧化碳浓度和气孔限制值在光照强度增加过程中表现出不同的变化趋势。[结论]叶片水势较高时造成光合速率下降的因素是非气孔因素,叶片水势较低时气孔因素是造成光合速率下降的主要因素。

[Objective] The aim was to explore the physiological mechanism of photosynthetic characteristics in strawberry and provide theoretical guidance for its seedling raising and open cultivation.[Method] With strawberry variety Daselect as material,the influences of different light intensities on the photosynthesis of strawberry in fruiting stage under 3 leaf water potentials of-1.28、-3.58 and-5.56 MPa were studied.[Result] The light intensity had significant influence on the photosynthetic rate of strawberry in fruiting stage and the peak value of photosynthetic rate appeared at the light intensity in 1 200～1 500 μmol/（m^2·s）.The higher the leaf water potential was,the more obvious the influence of light intensity on photosynthetic rate was.The stomata conductance of leaf decreased along with the increment of light intensity and the decreasing trend on stomata conductance of leaf with lower water potential was more obvious.The intercellular carbon dioxide concentrations and stomata limiting values of leaves with different water potentials showed different change trends in the course of increasing light intensity.[Conclusion] When the leaf water potential was higher,the factors causing the photosynthetic rate to decrease were non-stomata factors.When the leaf water potential was lower,the stomata factor was the main factor causing the photosynthetic rate to decrease.