【摘要】 利用大型活动式防雨旱棚 ,人工控制不同土壤含水量 ,全生育期系统研究了轻度及严重土壤干旱胁迫对夏玉米根系活力、叶片相对含水量、离体叶片保水力和根、叶质膜透性的影响 .结果表明 :土壤干旱胁迫下 ,玉米叶片相对含水量下降、离体叶片保水力降低 ;叶片及根系质膜透性上升 ,并且根的质膜透性比叶片上升快 ,根系活力下降 ;在干旱胁迫下 ,根系、叶片质膜透性与叶片相对含水量呈负相关 ,而根系、叶片质膜透性与离体叶片保水力呈显著正相关 ,根系膜透性与叶片膜透性也呈显著正相关 ,维持根系活力与保持较高的叶片含水量有密切关系 .另外 ,由于严重水分胁迫处理的上述特性和充分供水处理差异显著 ,而轻度胁迫和充分供水不显著 ,因此可以认为轻度水分胁迫 ,即土壤含水量为田间持水量的 6 0± 5 %为夏玉米正常生长发育的下限指标 ,可作为制定节水栽培措施的理论依据 .更多还原

【Abstract】 Using large moving water proof installations to regulate different soil water contents strictly,a systematic study was conducted to investigate the differences in root activity,leaves relative water content,water-holding capacity,plasma-membrane permeability of leaf and root in plants of summer maize during the whole growing period under light and severe soil drought stress.The results showed that:the leaf relative water content and roots vitality decreased,leave water-holding capacity declined apparently,the plasma membrane permeability of leave and roots enhanced under soil drought in maize.Under soil drought,the root and leaf plasma-membrane permeability were negatively related to the leaf relative water content,furthermore the root plasma-membrane permeability enhanced more sharply than the leaf.But the root and leaf plasma-membrane permeability were positively related to the leaves holding-water capacity,and the root plasma-membrane permeability were also positively related to the leaf plasma-membrane permeability,therefore maintaining the root activity is closely associated with keeping higher leaf relative water content in maize.In addition,because of the significant difference between severe water stress treatment and sufficient water supplying treatment above characteristics,and insignificant difference between light water stress and sufficient water supplying treatment.Light water stress [(60±5)%] can be as minimum index for normal growth and development of summer maize.更多还原