State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Plant Biol (Stuttg). 2020 Jul;22(4):615-622. doi: 10.1111/plb.13111. Epub 2020 Apr 15.
Phosphorus (P) is an important nutrient that can restrict plant growth. However, the influence of P deficiency on elemental homeostasis and application of the growth rate hypothesis in higher plants remain to be assessed. Two shrubs, Zygophyllum xanthoxylum and Nitraria tangutorum, were used as experiment material and subjected to five P addition treatments: 0, 17.5, 35.0, 52.5 and 70.0 mg P·kg soil. The biomass and relative growth rate of Z. xanthoxylum did not change with altered P supply. There was no significant difference in P concentration among the treatments for Z. xanthoxylum, but N. tangutorum showed an upward trend. The P stoichiometric homeostasis of Z. xanthoxylum was higher than that of N. tangutorum. For Z. xanthoxylum, available P in the rhizosphere improved significantly under extreme P deficiency conditions, and P concentrations in all treatments were lower than in N. tangutorum, showing that Z. xanthoxylum had stronger P absorption and P utilization capacity. No relationships between growth rate and C:N:P ratios were found in Z. xanthoxylum. The strong P efficiency, and high and stable dry matter accumulation, are likely contributors in maintaining stoichiometric homeostasis. In addition, the relatively high biomass accumulation and high P utilization efficiency for Z. xanthoxylum does not support the growth rate hypothesis for this species.
磷（P）是一种重要的营养物质，它可以限制植物的生长。然而，P 缺乏对元素平衡的影响以及生长率假说在高等植物中的应用仍有待评估。两种灌木，霸王和白刺，被用作实验材料，并进行了五种 P 添加处理：0、17.5、35.0、52.5 和 70.0 mg P·kg 土壤。霸王的生物量和相对生长率没有随着供 P 量的改变而改变。霸王的 P 浓度在处理之间没有显著差异，但白刺呈上升趋势。霸王的 P 化学计量内稳性高于白刺。对于霸王，根际有效 P 在极端 P 缺乏条件下显著提高，并且所有处理中的 P 浓度均低于白刺，表明霸王具有更强的 P 吸收和 P 利用能力。在霸王中，生长率与 C:N:P 比值之间没有关系。较强的 P 效率以及高且稳定的干物质积累，可能有助于维持化学计量内稳性。此外，霸王相对较高的生物量积累和高 P 利用效率不支持该物种的生长率假说。
