Abstract: In order to clarify the effect of drought stress on physiological characteristics and plant growth parameters of soybean cultivars with different drought resistance, this experiment took drought resistant variety (RD) and drought sensitive variety (SD) as material to analyze the effects of water stress on physiological and biochemical indexes and growth parameters of soybean during development period by pot cultivation method. The results showed that the physiological and biochemical indexes of RD and SD were not significantly different under normal water conditions. While after 15 d with drought stress, the activities of SOD and POD in RD plant leaves were 1.34～1.45 fold and 46～1.69 fold of that in SD, respectively. The hydrogen peroxide (H2O2) and malondialdehyde (MDA) in SD plant leaves were 1.80～2.35 fold and 1.09～1.46 fold of that in RD, respectively. In addition, under drought stress, the root biomass both above and below ground of RD was significantly higher than that of SD, and its root morphology parameters were much better than that of SD. The experimental results showed that for reponsing to drought condition, the drought resistant variety RD adjusted its body physiological changes, and optimized the parameters of root morphology to ensure the normal growth of plant and improve its responsing ability to drought stress.

Key words: drought stress, soybean variety, root system morphology, drought resistance

摘要： 为了明确干旱胁迫对不同抗旱大豆品种生理特性及植株生长参数的影响，选取了抗旱(RD)和不抗旱(SD)品种为材料，利用盆栽方法，分析大豆营养生长期在水分胁迫下对不同品种大豆生理生化指标及生长参数的影响。结果显示，在正常浇水条件下，RD和SD品种植株叶片中与抗旱相关的生理生化指标差异不明显，而在水分胁迫15 d后，RD植株叶片中SOD和POD活性分别为SD植株叶片的1.34～1.45倍和1.46～1.69倍，SD植株叶片中的过氧化氢（H2O2）和丙二醛（MDA）为RD植株叶片中的1.80～2.35倍1.09～1.46倍。另外，在干旱胁迫条件下，发现RD地上部和根部生物量均明显高SD品种，且其根系形态参数明显优于SD品种。实验结果表明在干旱胁迫条件下，抗旱品种植株通过调节体内生理变化和优化根系形态参数来响应外界环境，从而保证在干旱条件下植株能正常生长，提高干旱胁迫的响应能力。

关键词: 干旱胁迫, 大豆品种, 根系形态, 抗旱性