冬小麦根系对水分胁迫期间和胁迫后效的响应

 为揭示土壤水分胁迫期间和胁迫后效对植株根系生物量累积的影响，本文以冬小麦为对象，利用温室盆栽试验结果对其做了分析。结果表明，土壤水分在胁迫期间和胁迫后效对根重的抑制量不同，主要受胁迫程度和胁迫持续时间的影响；在胁迫期间，不同水分处理的根重抑制量源于此期间的胁迫强度，且重度胁迫处理大于中度胁迫处理；在胁迫解除后，尽管胁迫后效对根重的影响仍表现在相应时段的胁迫强度上，但是短期胁迫处理大于长期胁迫，中度胁迫大于重度胁迫处理；分析不同水分胁迫条件下的冬小麦根系的受抑制状况，集中表现为在短期胁迫和长期中度胁迫处理中，根重抑制量主要归因于胁迫后效应作用下的胁迫强度；而长期重度胁迫处理对根的抑制量源于胁迫期间的胁迫强度。结合前期的成果可见，水分胁迫对根生长的影响是源于前一个生育期已形成的基础、此生育期的环境响应以及前一个生育期环境效应的滞后作用的综合结果。

Response of Winter Wheat Root to the Effect and the After-Effect of Soil Water Stress

To reveal the effect and after-effect of soil water stress on winter wheat, the article employs the experimental results carded out in the greenhouse. The results showed that the root-restricted weights varied with stress degrees and stress times during and after water stress. In the course of stress, the chief reason restricting the weight of roots was the stress intensity at this time, and that of severe stress treatment was larger than that mild of stress treatment. After water stress was relieved, the results of the after-effect of soil water stress on root growth were that the stress intensity of short-time and mild stress was larger than that of long-time and severe stress. Compared the two-stage stress intensities, root-restricted weight resulted from after-effect intensity of stress of short-time treatment, the mild stress treatments and long-time stress treatment; while that resutted from the stress of severe, long-time stress treatment. In general, the effects of water stress on roots could be attributed to three aspects. The three facts, which are a basis formed at previous stage, the after-effect of water condition before this stage and the influence of water at this stage, lead to the characters of root at any growth stage.