对田间条件下不同类型和强度的干旱胁迫对黑麦草 ( L olium perenne)实验种群物质生产与水分利用特征的影响进行了研究。实验结果表明 :在周期性和持续性胁迫条件下 ,轻度与中度胁迫对草群干物质产量的影响相接近并与对照无显著差异 ,重度胁迫导致干物质产量的降低 ;渐进性胁迫条件下轻度胁迫对干物质产量的影响与对照相接近 ,中度和重度胁迫导致产量的降低 ;在每一种胁迫类型下植物地上部绿色部分的干物质含量与其干物质产量呈反向对应关系 ;草群干物质产量与栽植桶水分散失量之间呈极显著的直线关系 ;周期性胁迫条件下中度胁迫提高了草群水分利用效率 ,持续性和渐进性胁迫条件下草群水分利用效率对干旱胁迫强度的反应随生长季节推移而有所改变 The effects of different types and intensities of drought stress under field conditions on the material production and water use characteristics of experimental population in Lolium perenne were studied. The results showed that under the condition of periodic and continuous stress, the effect of mild and moderate stress on the dry matter yield of grass group was close to that of the control, but the severe stress resulted in the decrease of dry matter yield. The progressive stress condition The effects of mild stress on dry matter yield were similar to those of the control, and moderate and severe stress resulted in the decrease of yield. The dry matter content of the green part of plant aboveground was inversely correlated with the dry matter yield under each stress type ; The dry matter yield of grassland and the water loss of planting barrels had a very significant linear relationship; moderate stress increased the water use efficiency of grassland under continuous stress conditions, and the water use efficiency of grassland under continuous and progressive stresses The response of drought stress intensity changed with the growth season