不同灌水量对干旱区枸杞叶片结构、光合生理参数和产量的影响

宁夏枸杞是我国重要的药用植物资源.为确定宁夏枸杞的适宜灌溉量，在人工控水条件下，研究了不同月灌溉定额对宁夏枸杞叶片结构、光合生理以及果实产量的影响.结果表明：月灌水定额＜900 m³·hm^-2时，随着灌水量的增加,枸杞的叶面积、叶片厚度、栅栏组织厚度和叶片结构紧密度、叶片光合速率、瞬时水分利用效率、气孔限制值和枸杞果实产量显著增加，而气孔密度和胞间CO₂浓度则呈下降趋势;月灌水定额＞900 m³·hm^-2以后，叶片胞间CO₂浓度随月灌溉定额的增加呈上升趋势, 而叶面积、气孔密度和枸杞果实产量变化不显著，其他指标均呈相反的变化趋势.枸杞叶片蒸腾速率和气孔导度值以450 m³·hm^-2处理最高，分别达8.02和324 mmol·m^-2·s^-1;其他处理均低于对照.在节水条件下，900 m³·hm^-2的月灌溉定额较适合枸杞的灌溉.

Effects of irrigation amount on leaf structure,photosynthetic physiology,and fruit yield of Lycium barbarum in arid area

Lycium barbarum is an important traditional medicinal plant in China. Under controlled condition, a field experiment was conducted to study the effects of different monthly irrigation quota on the leaf structure, photosynthetic physiology, and fruit yield of L. barbarum, aimed to determine an appropriate irrigation amount for the plant. When the monthly irrigation quota was less than 900m³·hm^-2, the leaf area, leaf thickness, palisade tissue thickness, cell tense ratio (CTR), net photosynthetic rate (P_n), intrinsic water use efficiency (WUE), stomatal limitation value (L_s), and fruit yield of L. barbarum all increased significantly with monthly irrigation quota, while leaf stoma density and intercellular CO₂ concentration (C_i) showed a reverse trend.When the irrigation quota was more than 900 m³·hm^-2, the C_i increased with irrigation quota, the leaf area, stoma density, and fruit yield had no obvious change, whereas the other indices showed a reverse trend. The leaf transpiration rate and G_s were the highest at irrigation quota 450 m³·hm^-2, being 8.02 and 324 mmol·m^-2·s^-1, respectively;whereas at other irrigation quota, these two indices were lower than the control. In terms of saving water, the monthly irrigation quota 900 m³·hm^-2was more appropriate for Lycium barbarum.