中文摘要：

通过盆栽人工模拟干旱试验,研究了全生育期中度干旱胁迫对不同耐旱性玉米杂交种（耐旱：京科628;不耐旱：农大95）产量及根系生理特性的影响.结果表明：干旱胁迫下,耐旱玉米产量比对照减少33.7%,不耐旱玉米则比对照减少62.3%.干旱胁迫下,玉米根系生物量降低且最大值出现时间提前,与对照相比,不耐旱玉米根冠比升高,耐旱玉米根冠比前期升高后期降低;根系活力降低,不耐旱玉米根系活力降低幅度大于耐旱玉米;根系超氧化物歧化酶（SOD）活性前期高于对照后期低于对照,耐旱玉米根系SOD活性开始低于对照的时间比不耐旱玉米晚;根系丙二醛（MDA）含量升高,随干旱胁迫处理时间的延长,不耐旱玉米MDA含量比对照升高的幅度大于耐旱玉米;根系可溶性蛋白含量降低,不耐旱玉米的降低幅度大于耐旱玉米.干旱胁迫下耐旱玉米杂交种根系活力？根系SOD活性及可溶性蛋白含量较高,减缓了根系的衰老进程,延长了根系功能期,这可能是耐旱玉米杂交种在干旱胁迫下仍能获得较高产量的重要原因之一.

英文摘要：

A pot experiment was conducted to study the effects of simulated moderate drought in whole growth period on the grain yield and root physiological traits of drought-tolerant maize variety JK-628 and drought-sensitive maize variety ND-95.Compared with the control,the grain yield of JK-628 and ND-95 under the stress of moderate drought was decreased by 33.7% and 62.3%,respectively.Under drought stress,the root biomass of the two varieties decreased,with the maximum value appeared ahead.The root/shoot ratio of JK-628 increased at early growth stage but decreased at late growth stage,while that of ND-95 increased all along.ND-95 had a larger decrement of root activity than JK-628.The root SOD activity in drought-stress plants was higher in prophase but lower in anaphase,compared with that in the control,and the time of SOD activity begun to lower was later for JK-628 than for ND-95.The root MDA content in drought-stress plants was increased,and the increment was much higher for ND-95 than for JK-628.In addition,the root soluble protein content in drought-stress plants was decreased,and ND-95 had a larger decrement than JK-628.In a word,under drought stress,the root activity,SOD activity,and soluble protein content of JK-628 were higher than those of ND-95,which could slow down the root aging process and prolong the root functional period,possibly being one of the important factors of getting high yield of drought-tolerant maize under drought stress.