覆膜条件下冬小麦根系生理特性及其空间分布变化

覆膜条件下测定了冬小麦的根系活力与吸收面积,研究其空间分布情况。结果表明,在水平方向上,TTC还原量和TTC还原强度均随着离主茎距离的增加而减少;在垂直方向上,TTC还原量随着土层深度的加深而递减,TTC还原强度,返青期由上而下递减,开花期则上下土层无差异。根系总吸收面积和活跃吸收面积,在水平方向和垂直方向的变化与TTC还原量相同。覆膜处理并没有改变以上各指标的空间分布状态。但返青期水平方向的比吸收面积和比活跃吸收面积的变化趋势随覆盖地膜与否而不同,不覆膜处理由近到远递减,覆膜处理则无差异。返青期比吸收面积和比活跃吸收面积的垂直方向变化以及开花期二者的水平和垂直方向变化均无明显差异。根系活力与根系总吸收面积、活跃吸收面积呈极显著正相关。

The physiological characteristics of winter wheat roots and its spatial distribution under mulching plastic film condition

The spatial distribution of the winter wheat roots was studied by determining its root activities and absorbing areas under mulching plastic film condition. The results indicate that the root TTC reductive amounts and intensities were gradually decreased with the increase of distance from the plant stem in a horizontal range of 0-10 cm. From soil surface to 60 cm deep layer, TTC reductive amounts were gradually decreased and so were the root TTC reductive intensities at wheat reviving stages while there was no difference between different soil depths at flowering stage. Changes of total root absorbing area and actively absorbing area had the same trend as those of TTC reductive amounts either in the horizontal or the vertical range. Although plastic mulching did not change the spatial distribution of TTC reductive amounts and intensities, the specific absorbing area and specific actively absorbing area were different with mulching and without mulching at wheat reviving stage. Without mulching, the difference gradually decreased from a distant point of the plants to that close to the plants; with mulching, however, no difference was found in different points of the soil. The specific absorbing area and specific actively absorbing area had no significant difference at different depth from 0 to 60 cm at reviving stage while at flowering stage no difference was also found either in horizontal direction. The root activity was significantly correlated with both total roots absorbing area and actively absorbing area.