Background and aims Plasticity of plants refers to their ability to produce different phenotypes in different environments. Plants show plasticity aboveground as well as belowground. The influence of the arbuscular mycorrhizal fungal (AMF) symbiosis on root plasticity is poorly known. This study aimed to quantify plasticity of root-system related, morphological, physiological or mycorrhizal traits along a soil phosphorus (P) supply gradient. Methods Six varieties of maize ( Zea mays L.) were grown in pots with or without AMF at five rates of P supply. Fifteen root traits were measured and calculated after seven weeks of growth. Results Root system traits (biomass and length) and physiological traits (phosphatase activity at the root surface and in the rhizosphere) showed high plasticity along the P gradient, whereas morphological traits (specific root length and root diameter) exhibited low plasticity. Mycorrhizal presence reduced root-system plasticity (biomass and length), increased morphological-trait plasticity (specific root length and proportion of fine roots), but had little effects on other traits. Conclusion Our results indicate that trait plasticity related to the root system constitutes the most important adaptive strategy for maize to variation in P supply, and that the mycorrhizal symbiosis reduces root-system plasticity.

中文翻译：

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菌根对沿磷供给梯度的 6 个玉米品种根系性状可塑性的影响

背景和目的植物的可塑性是指它们在不同环境中产生不同表型的能力。植物在地上和地下都表现出可塑性。丛枝菌根真菌 (AMF) 共生对根可塑性的影响鲜为人知。本研究旨在量化沿土壤磷 (P) 供应梯度的根系相关、形态、生理或菌根性状的可塑性。方法 六个品种的玉米 (Zea mays L.) 在有或没有 AMF 的盆中以五种磷供应率种植。在生长七周后测量并计算了 15 个根性状。结果根系性状（生物量和长度）和生理性状（根表面和根际的磷酸酶活性）显示出沿 P 梯度的高可塑性，而形态特征（比根长和根径）表现出低可塑性。菌根的存在降低了根系的可塑性（生物量和长度），增加了形态性状的可塑性（特定的根长和细根的比例），但对其他性状几乎没有影响。结论 我们的结果表明，与根系相关的性状可塑性构成了玉米对磷供应变化最重要的适应性策略，菌根共生降低了根系可塑性。