不同灌溉模式下光合有效辐射与水稻叶片水分利用效率关系研究

根据江西省示范区晚稻节水灌溉试验资料,研究了不同灌溉模式下叶片水分利用效率随光合有效辐射的变化规律,分析了光合有效辐射与叶片水分利用效率的主要影响因子,气孔导度、胞间CO2浓度以及叶气温差的关系。结果表明:水稻叶片水分利用效率随光合有效辐射的增大表现出先增大后下降的变化趋势,二者之间表现出较好的二次曲线关系;光合有效辐射在500~900μmol/(m2.s)范围内,叶片水分利用效率均大于7.0μmolCO2/mmolH2O;控制灌溉模式下,水稻叶片水分利用效率略大于常规灌溉模式下的单叶水分利用效率,但无明显差异;光合有效辐射与气孔导度、胞间CO2浓度之间表现出较好的多项式关系,与叶气温差呈明显的直线关系,它们的关系从一定程度上揭示了光合有效辐射影响水稻叶片水分利用效率的生理机制。

Relationship Between PAR and Water Use Efficient in Rice Leaf under Different Irrigation Models

Based on the controlled irrigation experiment on rice in Jiangxi province,the"863"national special project,the relationships between Photosythetically Active Radiation(PAR) and Stomata Conductance(C),Interstellar CO_2 Concentration(Ci) and Temperature Difference between Leaf and Air(△T) were analyzed.Effect of PAR on Leaf Water Use Efficient(LWUE) under two different irrigation models(the controlled irrigation and the regular irrigation) was studied.Results show that: LWUE increased at first and decreased then with the rising of PAR.Quadratic equation was found between LWUE and PAR,and LWUE was more than 7.0 μmolCO_2/mmolH_2O when PAR varied between 500~900 μmol/(m~2·s).LWUE of controlled irrigation was bigger than that of regular irrigation,but no significant difference between them.Polynomial expression and linear expression existed between PAR and C and Ci,and △T separately,which uncover the mechanism of the effect of PAR on LWUE.