超高产夏玉米根系时空分布特性

比较不同产量水平夏玉米品种根系时空分布的差异，探讨超高产夏玉米品种的根系时空分布特性，为制定高产栽培管理措施提供依据。以超高产夏玉米品种登海661（DH661）为试材，普通品种郑单958（ZD958）为对照，在大田条件下采用土壤剖面取样方法研究了超高产夏玉米DH661与ZD958根系时空分布的差异。在整个生育时期，超高产夏玉米DH661根系干重、根系TTC还原强度、根系TTC还原总量、根系总吸收面积及活跃吸收面积均显著高于ZD958（P0.05），且抽雄后DH661根系干重、吸收面积及活跃吸收面积在60200 cm土壤深层中所占比例显著高于ZD958（P0.05），表明DH661的根系在土壤深层分布多，与土壤接触的有效面积大，生育后期仍保持较高的根系活力，对养分的吸收转运能力强。超高产夏玉米DH661具有发达的根系，且土壤深层根系数量多，根系活力高，有利于吸收深层土壤中较多的水分和养分。与土壤接触的有效面积大，对养分吸收转运能力强，有利于根系获得较多的营养物质，促进地上部光合性能的提高，为地上部籽粒的充实提供保障。

Temporal and spatial distribution characteristics of super-high-yield summer maize root

The aim of this study is to investigate the temporal and spatial distribution characteristics of roots of super-high-yield summer maize by comparing root characteristics of different summer maize cultivars.High-yield cultivar,Denghai661(DH661),and normal-yield cultivar,Zhengdan958(ZD958),were selected as material.The differences in temporal and spatial distribution characteristics of roots of the two cultivars in fields were studied using the soil profile sampling method.The results show that the dry root weight,TTC reducing capacity,TTC reducing quantity,absorbing area and active absorbing area of DH661 are all significantly higher(P<0.05) than those of ZD958 through the whole growth stages,and after the tasseling,the proportion of the dry root weight of DH661 are significantly higher(P<0.05) than that of ZD958 in the deep soil(60-200 cm).These results indicate that more water and nutrients are absorbed and transported by roots of super-high-yield DH661 which has the domination in root spacing distribution,number of roots in deeper layers,the effective touching area with soil and root activity at the later growth stages.As for DH661,it has a larger root system and stronger root function.The larger root system can increase root activity,deep root distribution and promote larger shoot development.All in all,because of the root characteristics,the DH661 can uptake more water and nutrients from the soil,promote the shoot growth well and supply the abundant filling matter.Therefore,DH661 can gain higher yield because it has a better root system.