Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA.
School of Biosciences, University of Nottingham, Sutton Bonington, Leicestershire, LE12 5RD, UK.
New Phytol. 2019 Jul;223(2):548-564. doi: 10.1111/nph.15738. Epub 2019 Mar 21.
Nutrient-efficient crops are a solution to the two grand challenges of modern agriculture: improving food security while reducing environmental impacts. The primary challenges are (1) nitrogen (N) and phosphorus (P) efficiency; (2) potassium (K), calcium (Ca), and magnesium (Mg) efficiency for acid soils; and (3) iron (Fe) and zinc (Zn) efficiency for alkaline soils. Root phenotypes are promising breeding targets for each of these. The Topsoil Foraging ideotype is beneficial for P capture and should also be useful for capture of K, Ca, and Mg in acid soils. The Steep, Cheap, and Deep ideotype for subsoil foraging is beneficial for N and water capture. Fe and Zn capture can be improved by targeting mechanisms of metal mobilization in the rhizosphere. Root hairs and phenes that reduce the metabolic cost of soil exploration should be prioritized in breeding programs. Nutrient-efficient crops should provide benefits at all input levels. Although our current understanding is sufficient to deploy root phenotypes for improved nutrient capture in crop breeding, this complex topic does not receive the resources it merits in either applied or basic plant biology. Renewed emphasis on these topics is needed in order to develop the nutrient-efficient crops urgently needed in global agriculture.
提高粮食安全的同时减少环境影响。主要挑战是（1）氮（N）和磷（P）效率；（2）钾（K）、钙（Ca）和镁（Mg）在酸性土壤中的效率；（3）铁（Fe）和锌（Zn）在碱性土壤中的效率。根系表型是这些方面的有前途的选育目标。表土层觅食理想型有利于磷的捕获，对于酸性土壤中 K、Ca 和 Mg 的捕获也应该有用。针对下层土壤觅食的“陡峭、廉价和深”理想型有利于氮和水的捕获。通过靶向根际金属动员机制，可以提高 Fe 和 Zn 的捕获。在选育计划中，应优先考虑减少土壤探测代谢成本的根毛和表型。养分高效作物应在所有投入水平提供益处。尽管我们目前的理解足以将根系表型用于作物选育中提高养分的捕获，但这个复杂的主题在应用或基础植物生物学中都没有得到应有的重视。为了开发全球农业急需的养分高效作物，需要重新强调这些主题。
