家榆和金叶榆光合·蒸腾及荧光参数对水分胁迫的响应

目的]探讨家榆和金叶榆抗旱能力的差异。方法]设置4个土壤水分梯度,用2年生家榆和金叶榆幼苗进行盆栽控水试验,利用GFS-3000便携式光合作用荧光测量系统测定试验苗的光合、蒸腾和荧光参数。结果]随水分胁迫程度的加剧,家榆和金叶榆光合速率、蒸腾速率、水分利用效率、气孔导度均呈下降趋势;水分胁迫程度越高,金叶榆光合速率比家榆下降的幅度越小;在重度水分胁迫条件下,金叶榆的蒸腾速率、非光化学猝灭明显低于家榆,叶片气孔导度、叶绿素荧光参数光化学猝灭则明显高于家榆。结论]在干旱条件下,金叶榆的抗干旱能力、自我调节能力、适应环境的能力较家榆更强,适应重度干旱环境的潜力更大。

Research on the Response of the Photosynthesis,Transpiration and Fluorescence Index of Ulmus pumila L.and Ulmus pumila cv.jinye to Water Stress

Objective] The difference in the drought tolerance between Ulmus pumila L.and Ulmus pumila cv.jinye was analyzed.Method] The potted experiment in the drought tolerance of the seedlings of 2 year-old Ulmus pumila L.and Ulmus pumila cv.jinye that were planted in soil with 4 gradient levels of moisture and the photosynthesis,transpiration and fluorescence parameter of the seedlings were measured with GFS-3000 portable photosynthesis measurement system.Results] With the intensification of water stress,the photosynthetic rate,transpiration rate,water-using efficiency,stomatal conductance of Ulmus pumila L.and Ulmus pumila cv.jinye showed a downward trend and the higher the degree of water stress was,the smaller the declining degree of Ulmus pumila cv.jinye photosynthetic rate was than that of Ulmus pumila L.Under the condition of severe water stress,the transpiration rate and non-photochemical quenching of Ulmus pumila cv.jinye was significantly lower than these of Ulmus pumila L.and the stomatal conductance,chlorophyll fluorescence parameter and non-photochemical quenching of Ulmus pumila cv.jinye were significantly higher these of Ulmus pumila L.Conclusion] In dry conditions,the ability of Ulmus pumila cv.jinye in drought resistance,self-regulation and adaptable to environment was stronger than these of Ulmus pumila L.and Ulmus pumila cv.jinye was with even greater potential in severe drought environment.