采用负水头灌溉盆栽装置,对充分灌溉(对照)、中度亏缺灌溉和重度亏缺灌溉(土壤相对含水量分别为65.63% ~84. 38%、26. 04% ~31. 51%和6. 63% ~15. 44%)条件下涝峪薹草(Carex giraldiana Kük.)、矮丛薹草(C.humilis Leyss.)、披针叶薹草(C. lanceolata Boott)和青绿薹草(C. breviculmis R. Br.)的生长和光合特性的差异进行了研究。结果表明: 随土壤相对含水量的降低,4 种植物地上和地下部分的生长量、根冠比、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和光能利用效率(SUE)均逐渐降低,胞间CO2 浓度(Ci)逐渐增加,而水分利用效率(WUE)总体上呈现波动的变化趋势。在中度亏缺灌溉条件下,4 种植物地上和地下部分生长量均低于对照,但叶片未枯黄;而在重度亏缺灌溉条件下,4 种植物地上和地下部分生长量均显著低于对照,且部分叶片枯黄;总体上看,在亏缺灌溉条件下4 种植物的根冠比均显著低于对照。在中度亏缺灌溉条件下,4 种植物的Pn、Tr、Gs 和SUE 值均低于对照而Ci 值均高于对照,但总体上差异不显著;仅青绿薹草的WUE 值高于对照,其他3 种植物的WUE 值均略低于对照。在重度亏缺灌溉条件下,4 种植物的Pn、Tr、Gs 和SUE 值均显著低于对照,Ci 值均显著高于对照;仅披针叶薹草的WUE 值略低于对照,其他3 种植物的WUE 值均高于对照。研究结果显示:供试的4 种薹草属植物均对亏缺灌溉有一定的耐性;亏缺灌溉对4 种植物地下部分生长的影响大于地上部分;非气孔因素是导致其Pn 降低的主要原因。

Using pot system with negative-pressure water supply, differences of growth and photosynthetic characteristics of Carex giraldiana Kük., C. humilis Leyss., C. lanceolata Boott and C. breviculmis R. Br. under sufficient irrigation (CK), moderate and heavy deficit irrigations (relative water content in soil 65. 63% -84. 38%, 26. 04% - 31. 51% and 6. 63% -15. 44%, respectively) were studied. The results show that with decreasing of relative water content in soil, growth increment of above-and under-ground parts, root-shoot ratio, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance ( Gs) and solar energy utilization efficiency ( SUE ) all decrease gradually, intercellular CO2 concentration (Ci) increases gradually, while water utilization efficiency (WUE) generally appears a fluctuant change trend. Under moderate deficit irrigation condition, growth increment of above-and under-ground parts of four species is lower than that of the control, but leaves do not appear wilting and yellowing, while under heavy deficit irrigation condition, that is significantly lower than that of the control and some leaves become wilting and yellowing. Generally, root-shoot ratio of four species under deficit irrigation condition is significantly lower than that of the control. Under moderate deficit irrigation condition, values of Pn, Tr, Gs and SUE of four species all are lower while Ci value is higher than those of the control with no significant difference generally; and only WUE value of C. breviculmis is higher while that of other three species is slightly lower than that of the control. Under heavy deficit irrigation condition, values of Pn, Tr, Gs and SUE of four species all are significantly lower while Ci value is significantly higher than those of the control; and only WUE value of C. lanceolata is slightly lower while that of other three species is higher than that of the control. It is suggested that four species tested all have a certain resistance to deficit irrigation. Effect of deficit irrigation on above-ground part growth of four species is greater than on their under-ground part. And non stomatal factors are the main causes led to Pn decreasing.