Local nitrogen application increases maize post-silking nitrogen uptake of responsive genotypes via enhanced deep root growth
Local nitrogen application increases maize post-silking nitrogen uptake of responsive genotypes via enhanced deep root growth
复制标题
DOI：
10.1016/j.jia.2022.07.003
复制
发表时间：
2022-07
影响因子：
4.8
通讯作者：
Zhe Chen;Wei Ren;Xia Yi;Qiang Li;H. Cai;Ali Farhan;Lijuan Yuan;G. Mi;Qingchun Pan
中科院分区：
文献类型：
--
作者：
Zhe Chen;Wei Ren;Xia Yi;Qiang Li;H. Cai;Ali Farhan;Lijuan Yuan;G. Mi;Qingchun Pan
氮（N）在土壤中的分布不均匀，植物根系在富含N的土壤斑块中增殖。然而，不同基因型玉米根系对局部供氮的反应与氮吸收效率之间的关系尚不清楚。在这项研究中，评估了四个玉米品种，以探讨根系对局部施氮与氮吸收相关反应的基因型差异。一个分根系统建立水培生长的植物和两种方法的本地N的应用（本地带和本地打点）进行了研究。根长对氮素反应的基因型差异在水培和田间条件下高度相关（r>0.99）。在水培条件下，对氮素反应高的基因型ZD 958、XY 335和XF 32 D22在富氮区的侧根长和根生物量分别比对照高50-63%和36-53%，而LY 13基因型对氮素反应不高。在田间条件下，高响应基因型的根长在40-60 cm土层增加了66-75%，而LY 13的根长变化较小。此外，在高反应基因型中，局部施氮使吐丝后的氮吸收增加16-88%，使ZD 958的籽粒产量增加10- 12%。产量与40-60 cm土层根长呈显著正相关（r=0.39）。我们的结论是，当地施肥应用于高响应基因型，这可以在苗期快速识别，选择“本地N响应根”可以是一个有前途的性状在玉米育种高氮吸收效率。
Nitrogen (N) is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil patches. However, the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is unclear. In this study, four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake. A split-root system was established for hydroponically-grown plants and two methods of local N application (local banding and local dotting) were examined in the field. Genotypic differences in the root length response to N were highly correlated between the hydroponic and field conditions (r>0.99). Genotypes showing high response to N, ZD958, XY335 and XF32D22, showed 50–63% longer lateral root length and 36–53% greater root biomass in N-rich regions under hydroponic conditions, while the LY13 genotype did not respond to N. Under field conditions, the root length of the high-response genotypes was found to increase by 66–75% at 40–60 cm soil depth, while LY13 showed smaller changes in root length. In addition, local N application increased N uptake at the post-silking stage by 16–88% in the high-response genotypes and increased the grain yield of ZD958 by 10–12%. Moreover, yield was positively correlated with root length at 40–60 cm soil depth (r=0.39). We conclude that local fertilization should be used for high-response genotypes, which can be rapidly identified at the seedling stage, and selection for “local-N responsive roots” can be a promising trait in maize breeding for high nitrogen uptake efficiency.