水分胁迫下两种草坪草的渗透调节与抗旱性的关系

Relationship Between Osmotic Adjustment and Drough Resistance in two Turf GrassesUnder Water Stress.

在土壤干旱情况下研究了紫羊茅、黑麦草对渗透胁迫的反应以及各项水分参数的变化。结果表明，土壤水分胁迫下，两品种叶片相对含水量、水势、渗透势、膨压势均随胁迫天数、胁迫强度的增加而下降；同级胁迫程度，抗旱性较强的紫羊茅各指标均高于抗旱性较弱的黑麦草；胁迫解除后，两品种所有指标均回升，不表现渗透调节能力；水势与渗透势及膨压势均为线性关系，水势每变动１兆帕，渗透势变动紫羊茅０．６７６９＞黑麦草０．４６４３，而膨压势降低单位数紫羊茅０．３６１５＜黑麦草０．４５４２；渗透调节能力为紫羊茅＞黑麦草。

he responses of two turf grasses to the osmotic stress and the change of water indexunder the water stress conditions were studied. The results showed that RWC,ψw,ψsand ψP in the two grasses gradually reduced with the increase of stress duration andstress intensity. At the same intensity the index of red fescue (Festuca rubra)is higherthan that of the perennial ryegrass(Lolium perenne).The indexes of the two grassesincreased after rewatering the abilities of osmotic adjustment slowly disappeared.Theresults of regression analysis indicated that ψw,ψs and ψp were subjected to linear rela-tionship.