中文摘要：

以高产夏玉米品种郑单958（浅根型,ZD）和登海661（深根型,DH）为材料,于大喇叭口期（V12）分别在距离植株两侧10 cm、20 cm、30 cm处垂直断根,断根深度60 cm,以不断根处理为对照,共设计8个处理（ZDCK、ZD10、ZD20、ZD30;DHCK、DH10、DH20、DH30）,研究了玉米植株两侧不同水平距离处根系对夏玉米籽粒灌浆及产量形成的调控作用。结果表明,ZD10、ZD20与DH10、DH20分别切断24.81%、11.69%与16.82%、7.52%的根系;ZD30与DH30各指标与CK间无显著差异,ZD10、ZD20产量分别下降13.09%、9.10%,显著大于DH10、DH20的产量降幅（9.81%、4.64%）,其产量下降原因主要是断根后两品种的穗粒数与千粒重降低,其中ZD20、ZD10穗粒数与千粒重较ZDCK分别下降4.90%、5.60%和4.37%、7.88%,DH20、DH10穗粒数与千粒重较DHCK分别下降3.38%、5.15%和1.15%、4.97%;断根后两品种实际库容与结实率均有不同程度下降;到达最大灌浆速率时的天数（Tmax）、灌浆速率最大时的生长量（Wmax）、最大灌浆速率（Gmax）、籽粒灌浆活跃期（P）、灌浆速率也均下降,断根处理对浅根型品种郑单958的影响更为显著。

英文摘要：

A field experiment was conducted using two summer maize cultivars, Zhengdan 958 （ZD, shallow root type） and Denghai 661 （DH, deep root type）. At the V12 stage, we cut roots vertically at different horizontal distance of 10 cm, 20 cm and 30 cm from maize plant in 60 cm soil depth, with no roots cutting as contrast check, which were referred to as ZDCK, ZD10,ZD20, ZD30 and DHCK, DH10, DH20, DH30 respectively. Roots of ZD10 and ZD20 decreased 24.81%, 11.69% and those of DH10, DH20 decreased 16.82%, 7.52% after cutting roots, respectively. Grain yield of summer maize decreased significantly after cutting roots, with a decrease of 13.09%, 9.10% for ZD10 and ZD20, respectively, and 9.81%, 4.64% for DH10 and DH20. After cutting roots, grains per ear and 1000-grain weight of ZD20, ZD10, DH20, and DH10 declined 4.90%, 5.60%, 4.37%, 7.88%, and 3.38%, 5.15%, 1.15%, 4.97%, respectively, which is the important factors resulting in lower grain yield. Grain sink and setting rate were also decreased to a different extent after cutting roots. Cutting roots decreased days to the maximum grain filling rate （Tmax）, weight at the time up to the maximum grain filling rate （Wreak）, maximum grain filling rate （Gmax）, the phase of active grain filling, and average grain filling rate of two cultivars, with more decrease in Zhengdan 958 than in Denghai 661.