在池栽条件下 ,用 32 P2 O5同位素示踪技术研究了高产小麦生育后期的群体根系活性及其垂直分布状况。结果表明 ,伴随着植株的衰老 ,高产小麦生育后期群体根系活性 (单位土体内的根系活性 )迅速下降 ,但存在品种间的差异。一般而言 ,正常落黄型品种在生育后期维持相对较高的群体根系活性。根系活性的垂直分布特点是 ,浅层根系的群体根系活性越来越小 ,而深层根系的群体根系活性则相对较高 ,且存在着随生育进程的推进 ,小麦群体根系活性向较深层土壤下移之趋势。不仅如此 ,不同深度土层根系吸收的 32 P在运转分配方面存在明显差异 ,即浅层根系吸收的 32 P较多地运往茎鞘等营养器官 ,深层根系吸收的 32 P较多地运往穗部等生殖器官 Under pond culture conditions, root activity and vertical distribution of high-yielding wheat at late growth stage were studied by 32 P2 O5 isotope tracing technique. The results showed that with the plant senescence, the root activity (root activity per unit of soil) of high-yield wheat decreased rapidly at the later growth stage, but there were differences among varieties. In general, normal yellowing varieties maintained relatively high population root activity during later growth period. The vertical distribution of root activity was that the root activity of the root system in the shallow layer was less and less, while the root activity of the root system in the deep root system was relatively high. The root activity of the root system of the root system moved deeper into the deeper layer Move the trend. In addition, there was a significant difference in distribution of 32 P absorbed by roots in different depths, ie, 32 P absorbed by shallow roots was more transported to vegetative organs such as stems and sheaths, and 32 P absorbed by deeper roots was transported to ears Other reproductive organs