Phosphorus (P) is an important macronutrient required for crop growth but a finite resource in agriculture. The objective of this study was to examine the effects of soybean seed size and seed P content on growth and P accumulation up to anthesis (30–40 DAP). Pot experiments were carried out in a greenhouse with 15 soybean genotypes of different seed size (TKW 146–304 g) and with two substrates differing in plant available P, i.e., low P (LP) at 6.17 mg kg⁻¹ vs. high P (HP) at 68.12 mg kg⁻¹ CAL-P. The observations included measurements of seed and shoot dry matter and P concentrations as well as root characteristics. In the case of LP, shoot P accumulation relied, to a large degree, on seed P reserves during the vegetative growth period. In the case of HP, however, the role of seed P is negligible with regard to absolute P uptake. Yet, a very close linear relationship between seed P and shoot P uptake was also confirmed at HP. Some genotypes reacted more positively than others on HP in biomass production and P uptake, but none of the selected genotypes showed an outstanding biomass production or P uptake under LP. Total root length or root surface area of soybean did not explain differences in P uptake between genotypes at either P supply level. Overall, no substantial genotypic differences were observed in P use efficiency under P deficiency apart from the effect of seed P reserves. We conclude that seed size can be considered an important trait when screening genotypes for fast early P accumulation and growth.

中文翻译：

---

大豆种子磷对花前芽磷吸收的重要性

磷 (P) 是作物生长所需的重要常量营养素，但在农业中是一种有限资源。本研究的目的是检查大豆种子大小和种子磷含量对生长和直至开花期（30-40 DAP）磷积累的影响。盆栽试验在温室中进行，具有 15 种不同种子大小的大豆基因型（TKW 146–304 g）和两种植物有效磷不同的底物，即 6.17 mg kg ^{-1 的}低磷 (LP)与高磷(HP) 68.12 mg kg ^-1CAL-P。观察结果包括对种子和芽干物质和 P 浓度以及根特征的测量。在LP的情况下，地上部磷的积累在很大程度上依赖于营养生长期的种子磷储备。然而，在 HP 的情况下，种子 P 在绝对 P 吸收方面的作用可以忽略不计。然而，在 HP 也证实了种子 P 和芽 P 吸收之间非常密切的线性关系。一些基因型在生物量生产和磷吸收方面对 HP 的反应比其他基因型更积极，但没有一个选定的基因型在 LP 下表现出突出的生物量生产或磷吸收。大豆的总根长或根表面积不能解释在任一磷供应水平下基因型之间磷吸收的差异。全面的，除了种子磷储备的影响外，在缺磷条件下磷的利用效率没有观察到显着的基因型差异。我们得出结论，在筛选快速早期磷积累和生长的基因型时，种子大小可以被认为是一个重要的性状。