Institute of Plant Sciences; Agricultural Research Organization (ARO), Gilat Research Center, Israel.
Institute of Soil, Water, and Environmental Sciences, Agricultural Research Organization (ARO), Gilat Research Center, Israel.
J Exp Bot. 2021 Apr 2;72(8):3307-3319. doi: 10.1093/jxb/erab060.
Precise phosphorus (P) application requires a mechanistic understanding of mineral effects on crop biology and physiology. Photosynthate assimilation, metabolism, and transport require phosphorylation, and we postulated that P is critical for the bloom and fruit-set of almond trees that rely on stored carbohydrate reserves. Hence, we studied the growth, physiology and carbohydrate dynamics in 2-year-old almond trees irrigated with P concentrations between 1 mg l-1 and 20 mg l-1. Almond trees attained maximal photosynthesis, transpiration, and growth by 6 mg P l-1 irrigation. Nevertheless, almond trees continued to extract P in 10 mg P l-1 and 15 mg P l-1 irrigations, which corresponded to larger yields. We attributed the augmented productivity to increased fruit-set (59% between 6 mg P l-1 and 15 mg P l-1), caused by more frequent (29%) honeybee visits. High P improved pollinator visitation by enabling almond trees to utilize more of their starch reserves for nectar secretion (which increased by ~140% between 6 mg P l-1 and 15 mg P l-1). This work elucidates the benefits of P fertilization to plant-pollinator mutualism, critical to almond productivity, and reveals novel indices for optimal P application in almond orchards.
精确的磷 (P) 应用需要对矿物质对作物生物学和生理学的影响有深入的了解。光合作用产物的同化、代谢和运输都需要磷酸化，我们假设 P 对依赖储存碳水化合物储备的杏仁树的开花和坐果至关重要。因此，我们研究了在磷浓度为 1 毫克/升至 20 毫克/升之间灌溉的 2 年生杏仁树的生长、生理和碳水化合物动态。杏仁树在 6 毫克 P l-1 灌溉时达到最大光合作用、蒸腾作用和生长。然而，杏仁树在 10 毫克 P l-1 和 15 毫克 P l-1 的灌溉中仍继续提取 P，这对应着更大的产量。我们将增加的生产力归因于更高的坐果率（6 毫克 P l-1 和 15 毫克 P l-1 之间增加了 59%），这是由于蜜蜂访问的频率更高（增加了 29%）。高磷通过使杏仁树能够利用更多的淀粉储备来分泌花蜜（在 6 毫克 P l-1 和 15 毫克 P l-1 之间增加了约 140%），从而提高了传粉者的访问量。这项工作阐明了磷施肥对植物-传粉者共生的好处，这对杏仁的生产力至关重要，并揭示了杏仁果园中最佳 P 应用的新指标。
