The plasticity of root distribution and nitrogen uptake contributes to recovery of maize growth at late growth stages in wheat/maize intercropping
The plasticity of root distribution and nitrogen uptake contributes to recovery of maize growth at late growth stages in wheat/maize intercropping
复制标题
小麦玉米间作中根系分布和氮素吸收的可塑性有助于玉米生长后期生长的恢复
DOI：
10.1007/s11104-019-04034-9
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发表时间：
2020-02-01
期刊：
影响因子：
4.9
通讯作者：
Li, Long
中科院分区：
文献类型：
--
作者：
Liu, Yi-Xiang;Sun, Jian-Hao;Li, Long
背景和目的以往的研究表明，竞争恢复原理是小麦/玉米间作高产的机制之一。然而，很少有研究关注晚熟物种恢复生长过程中根系形态和生理变化的影响。本研究旨在确定根系分布和氮（N）吸收对不同氮供应的恢复生长的潜在机制。方法在大田条件下，间作六施氮量和单作一施氮量小麦收获后，采用螺旋钻取样3次。结果间作玉米随着土壤氮浓度的增加，调整了根长密度（RLD）和根系分布，提高了单位根长的氮吸收量。土壤无机氮浓度对间作玉米的RLD有直接影响，且与地上部氮浓度有关。此外，与单作相比，与玉米间作的玉米每单位根长吸收的氮量多93%。结论我们的研究结果表明，晚熟物种的恢复生长涉及玉米根系结构的表型可塑性，而氮吸收的增强是由于从小麦收获前生长的地区获得了额外的土壤氮。
Background and aims Previous studies showed that the competition-recovery principle is one of the mechanisms underpinning overyielding in wheat/maize intercropping. However, few studies have focused on the effects of root morphological and physiological changes during the recovery growth of late-maturing species. The present study aimed to determine the mechanism underlying the recovery growth in terms of root distribution and nitrogen (N) uptake in response to different N supplies. Methods The roots of maize were sampled three times by auger after wheat harvest in the intercropping system with six levels of N application and sole crops at one N-application rate under field condition. Results Intercropped maize adjusted its root length density (RLD) and root distribution and enhanced its N absorption per unit root length with increasing soil N concentration. Soil inorganic N concentration had a direct influence on RLD of intercropped maize which was related to shoot N concentration. In addition, maize took up 93% more N per unit root length when intercropped with maize compared with sole cropping. Conclusions Our findings show that the recovery growth of late-maturing species involves phenotypic plasticity of maize root architecture, and the enhanced N uptake resulted from extra soil N acquired from the area where wheat was growing before its harvest.