水肥耦合对冬小麦不同生育期质膜透性的影响

在田间条件下研究水肥耦合对冬小麦各生育期叶片质膜相对透性的影响。试验结果表明：冬小麦叶片质膜相对透性与生育时期有关，总的趋势表现为冬前低，开春稍升；拔节期大幅降低，灌浆期逐渐增加，成熟期最大。冬灌前各处理质膜透性无差异。冬灌后，补水处理的质膜透性普遍降低，其中以高氮冬灌处理质膜透性的降幅最大，并随时间后移至拔节初期表现出明显的水肥正交互作用；而未补水处理的质膜透性均较高。拔节期施氮春灌处理对维持质膜稳定性有利，而不施氮春灌处理在起初有一定负效应，但随时间后移至灌浆初期表现为正效应。从灌浆期灌水前看，冬灌和春灌对维持质膜稳定性都有一定的正效应，大部分施肥补充灌溉处理较未补充灌溉处理质膜相对透性降低。灌浆期灌水的效果比较复杂，但后期同时追施氮肥和灌水处理质膜相对透性较低。

Coupling effects of water and fertilizer on the relative penetrability of cell membrane of winter wheat leaf

The coupling effects of water and fertilizer on the relative penetrability of cell membrane of winter wheat leaf were studied under field condition.The results showed that the cell membrane penetrability of winter wheat leaf was low before winter and higher in early spring.It was decreased rapidly at jointing stage and increased gradually at grain filling stage,and the highest appeared at ripe stage.There was no difference \{among\} all treatments before winter irrigation.With winter irrigation for the designed treatments,the relative penetrability of cell membrane was all reduced.Of those,the treatment with both high N application and irrigation resulted in great reduction of the penetrability,and a coupling effect of water and N fertilizer was found at early jointing stage for this treatment.In addition,the relative penetrability of cell membrane was higher for those the treatments without irrigation.At jointing stage,N addition and irrigation conducted together in spring benefited for maintaining the stability of the cell membrane.The treatment of spring irrigation alone had a certain negative effect during the early period,and didn't show positive effect until grain filling stage.Determination before irrigation at the grain filling stage,winter irrigation or spring irrigation was beneficial for the stability of the cell membrane.Compared with addition of N fertilizer alone,the relative penetrability of cell membrane was reduced for both N fertilization and irrigation treatments.Though the effect was complex after irrigation at grain filling stage,applying N and irrigation at late growth stage obviously reduced the relative penetrability of cell membrane.