供水深度与冬小麦根系发育的关系

The Relationship Between Water Supplying Depth and Root System Development of Minter Wheat

用冀84-5418小麦在温室条件硬塑料管内种植,研究供水深度、对其根系及冠层发育影响的结果表明:根系向纵深伸展较快,且处理间没有明显差异。根系总干重(初生根和次生根)挑旗前略呈指数增长,开花期出现低谷而后以较快速度增长,成熟期达最大。初生根重挑旗期达到峰值而后减少。主要发生在0～100cm土层,100cm以下土层内根重变化甚微。供水深度影响根系和冠层生物量的增长。供水深度对根的层次分布影响较大,地表和20cm层供水处理的100cm以上土层根系发育较多;40cm层供水对40cm以上土层中根系有一定抑制作用,中后期较明显,80cm层供水抑制次生根发育,上层根重显著降低,对深层根重影响较小。冠层生物量80cm处理增长明显减慢,开花前其它三处理差异不明显。最终单株生物量、单株穗数和单株粒重以浅层地下供水(20和40cm)表现较好。冠层和根系生长既相互依存,又相互抑制。挑旗前二者是同步的,挑旗至开花阶段地上部生长抑制了根系发育,开花至成熟阶段除80cm供水外,地上下部均快速增长。浅层地下根冠比较适宜,有利于籽粒的生产。

The development of root and canopy of winter wheat was etudied underdifferent water supplying depth treatment using cv.HB84-5418 grown in pla-stic tubes in the glasshouse,The results showed that the roots expanded down-wards quickly without any significant differences in the treatments.Total dryweight of roots(including seminal and nodal roots)increased exponentiallyprior to the booting stage,but depression occured at the flowering stage andthen grew at a fast rate and reached its maximum in the mature stage.Thedry weight of seminal roots,reached maximum prior to the booting stage andthen turned to decrease,The reduction mainly happened in 100—cm soil layer,but little change in water supplying patternsoccured below 100 cm soil layermight affect biomass production in both canopy and root differently.More rootsdeveloped above 100 cm soil layer for the treatments of surface and 20 cmdepth in water supply,especially after the booting.Water supplies in 40 cmsoil layer inhibited the root system above 40 cm soil layer more apparently inthe middle and late stages.Water supplies in 80-cm soil layer inhibited thenodal root development with remarkable root weight reduced in the upper soillayer,but little effect upon roots in the deep soil layer.The biomaass produ-ction in canopy in the treatment at 80 cm soil layer gradually reduced andthen there were no obvious differences in other three treatments prior to theflowering stage.Eventually,biomass produotion per single plant,ears andgrain weight per single plant showed better in water supplies in the shallowsoil layer(20～40cm deep).The growth of canopy and root system can notonly inter-depend upon each other but also inter-inhibite each other.Prior tothe booting the two are in synchronization.From the booting to the floweringstages,the wheat growth above the ground inhibited the root developmentfrom the flowering to the maturing stages,the wheat plant above and underthe ground grew fast except the plant parts in water supplies in 80 cm soillayer,and root canopy water supplies at the shallow soil layer developed sui-tably,whereby to be favourable to grain formation of winter Wheat.