Hawkesford Malcolm John, Riche Andrew B
Plant Sciences Department, Rothamsted Research, Harpenden, United Kingdom.
Front Plant Sci. 2020 Jul 29;11:1157. doi: 10.3389/fpls.2020.01157. eCollection 2020.
Globally it has been estimated that only one third of applied N is recovered in the harvested component of grain crops. This represents an incredible waste of resource and the overuse has detrimental environmental and economic consequences. There is substantial variation in nutrient use efficiency (NUE) from region to region, between crops and in different cropping systems. As a consequence, both local and crop specific solutions will be required for NUE improvement at local as well as at national and international levels. Strategies to improve NUE will involve improvements to germplasm and optimized agronomy adapted to climate and location. Essential to effective solutions will be an understanding of genetics (G), environment (E), and management (M) and their interactions (G x E x M). Implementing appropriate solutions will require agronomic management, attention to environmental factors and improved varieties, optimized for current and future climate scenarios. As NUE is a complex trait with many contributing processes, identifying the correct trait for improvement is not trivial. Key processes include nitrogen capture (uptake efficiency), utilization efficiency (closely related to yield), partitioning (harvest index: biochemical and organ-specific) and trade-offs between yield and quality aspects (grain nitrogen content), as well as interactions with capture and utilization of other nutrients. A long-term experiment, the Broadbalk experiment at Rothamsted, highlights many factors influencing yield and nitrogen utilization in wheat over the last 175 years, particularly management and yearly variation. A more recent series of trials conducted over the past 16 years has focused on separating the key physiological sub-traits of NUE, highlighting both genetic and seasonal variation. This perspective describes these two contrasting studies which indicate G x E x M interactions involved in nitrogen utilization and summarizes prospects for the future including the utilization of high throughput phenotyping technology.
据全球估计，在谷类作物的收获部分中，施用的氮只有三分之一被回收利用。这是对资源的惊人浪费，过度使用会产生有害的环境和经济后果。不同地区、不同作物以及不同种植系统之间的养分利用效率（NUE）存在很大差异。因此，在地方、国家和国际层面提高NUE需要针对当地和特定作物的解决方案。提高NUE的策略将包括改良种质以及优化适应气候和地理位置的农艺措施。有效解决方案的关键在于理解遗传学（G）、环境（E）和管理（M）及其相互作用（G×E×M）。实施适当的解决方案需要农艺管理、关注环境因素以及改良品种，这些品种要针对当前和未来的气候情景进行优化。由于NUE是一个具有许多促成过程的复杂性状，确定正确的改良性状并非易事。关键过程包括氮素捕获（吸收效率）、利用效率（与产量密切相关）、分配（收获指数：生化和器官特异性）以及产量和品质方面（籽粒氮含量）之间的权衡，以及与其他养分捕获和利用的相互作用。一项长期实验——位于洛桑试验站的Broadbalk实验，突出了过去175年中影响小麦产量和氮素利用的许多因素，特别是管理和年度变化。在过去16年中进行的一系列最新试验专注于分离NUE的关键生理亚性状，突出了遗传和季节变化。本文阐述了这两项对比研究，它们表明了氮素利用中涉及的G×E×M相互作用，并总结了未来的前景，包括高通量表型技术的应用。
