中文摘要：

以丰华占为研究材料，通过盆栽试验，在水稻生长的不同生育时期分别进行水分胁迫处理，研究其对水稻根系活力、叶片水势和保护酶活性的影响．结果表明，不同生育期干旱胁迫后叶片水势均显著下降，解除干旱后回复到对照水平；分蘖期、穗分化期、抽穗期、结实期干旱处理后根系活力分别比对照上升181．38％、27．32％、94．86％和93．47％，其中穗分化期、抽穗期干旱处理在解除干旱后均仍然显著高于对照．不同生育期干旱胁迫均造成叶片和根系的超氧化物歧化酶（SOD）活性显著提高，其中抽穗期控水后SOD活性提高幅度最大，叶片和根部SOD活性分别比对照提高44．30％和105．18％，且解除干旱后仍然高于对照．根系和叶片的过氧化物酶（POD）和过氧化氢酶（CAT）活性在不同生育期干旱处理后均显著上升，解除干旱后可回复到与对照接近的水平．研究还表明，无论干旱与否，叶片的SOD、POD和CAT活性均远远高于根部．

英文摘要：

Effects of water stress at different growing stages on root activity, leaf water potential, protective enzymes activity of leaf and root in rice variety, Fenghuazhan, were studied through pot experiment. The results showed that, leaf water potential was significantly decreased after water stress at different growth stages and it could be restored to the normal level after re-irrigation. Root activity after water stress was increased ing and filling by 181.38%, 27.32% , 94. 86% and 93.47% at tillering, panicle differentiation, headstages, and kept higher level than the control after re-irrigation at panicle differentiation and heading stage. Superoxide dismutase （ SOD ）, catalase （CAT） and peroxidase （ POD ） activity in leaf and root increased significantly after drought treatment, and restored to normal level after re-irrigation except that SOD activity were still higher than control when drought at panicle differentiation and heading stage were removed. SOD, POD and CAT activity in leaf was higher than in root whatever irrigation or drought.