以玉米杂交种郑单958为材料，比较研究了在7.5万株/hm2的条件下，分别于大喇叭口期去根和吐丝期去根处理对植株根系形态及产量的影响，以期为探明密植高产玉米群体是否存在根系冗余提供理论依据。结果表明：吐丝期去根处理的植株穗粒数、千粒重和产量较不去根植株分别提高了8.70%、4.74%和1.98%，而大喇叭口期去根处理的则分别降低了16.53%、10.29%和2.74%。吐丝期去根处理的植株地上部总干物重和分配至果穗中的干物质比例最高，较对照分别增加了0.72%和4.96%。2种去根处理显著增加了0-10cm土层内的根系长度，尤其增加了0.5-1.0mm毛细根的数量，利于对耕层水分和营养的吸收，大喇叭口期去根处理增加了各土层内的根系表面积和根体积，吐丝期去根处理增加了0-10cm土层内的根系表面积和根体积。研究认为，密植高产玉米群体存在根系冗余，在玉米吐丝期适当去根处理对玉米产量的提高具有促进作用。
英文摘要:
In order to make clear if root redundancy is exist in high density and high yield maize population, the effects of different root-cutting treatments on root morphology and grain yield were studied using maize hybrid Zhengdan 958 as material under planting density of 75000 plants/ha in the field. The treatment was done in large bell shaped stage (DR) and silking stage (TR), respectively. The results showed that compared with CK treatment, the grain number, 1000-grain weight and yield of TR treatment could be increased by 8.70%, 4.74% and 1.98%, respectively, while for DR treatment they could be reduced by 16.53%, 10.29% and 2.74%, respectively. With the advance of growth, the whole plant dry matter weight above ground and partitioning to ears were gradually increased, and TR treatment were 0.72% and 4.96% higher than that of CK. The root length in 0-10cm soil layer, especially the roothair length between 0.5-1.0mm in diameter which is conducive to absorb water and nutrients were increased. The root surface area and volume in each soil layer were significantly increased by DR treatment, while for TR treatment the increase was only in 0-10cm soil layer. It can
be deduced from the study that root redundancy is exist and maize yield could be improved by properly root cutting at silking stage for high planting density and high yield maize population.
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