Abstract: The mechanisms by which the root systems of invasive plants respond to nutrient and water deficiency remain poorly understood.In this study， we conducted a paired comparison between Asteraceae invasive plants （Senecio vulgaris， Symphyotrichum subulatum） and native plants （Senecio scandens， Aster ageratoides）， examined their root traits， Arbuscular Mycorrhizae Fungi （AMF） colonization rate， and biomass performance under normal and water and nutrient deficient conditions. The results showed that although both water and nutrient deficiencies reduced aboveground biomass and AMF colonization rates by more than 20% on average across all species， the invasive plants exhibited significantly greater aboveground biomass and higher AMF colonization rates compared to native plants. Nutrient deficiency significantly increased specific root length and specific root surface area， promoted root length and surface area of roots with diameters <0.5 mm， and reduced root tissue density in native plants， with average changes ranging from 8.23% to 32.64% in native plants. However， invasive plants showed opposite or no significant changes. With the exception of Symphyotrichum subulatum， water deficiency enhanced specific root length， specific root surface area， root length and surface area across all diameter classes， while reducing root tissue density in the other species. In summary， the invasive plants demonstrated stronger stress resistance. Under nutrient stress， invasive plants relied more on maintaining high AMF colonization， whereas native plants primarily depended on adjustments in root morphology. Under water deficiency， both invasive and native plants exhibited similar root adaptation strategies， but the invasive plants maintained higher AMF colonization. Combined stress responses tended to resemble those under single nutrient deficiency. These findings are important for elucidating the mechanisms underlying the adaptation of invasive plants to nutrient- and water-deficient environments.

Key words: Invasive plants, Water deficit, Nutrient deficiency, Arbuscular mycorrhizal fungi, Root morphological traits

摘要： 为探究入侵与本地近缘植物对水分和营养胁迫的根系适应机制，本研究比较了入侵植物欧洲千里光（Senecio vulgaris）、钻叶紫菀（Symphyotrichum subulatum）和本地植物千里光（Senecio scandens）、三脉紫菀（Aster ageratoides）的根系形态、丛枝菌根真菌（Arbuscular mycorrhizae fungi，AMF）侵染率及生物量等指标的差异，结果显示：水分和营养胁迫均使两类植物地上生物量和AMF侵染率下降超20%，但入侵植物仍保持显著更高的地上生物量与AMF侵染率。营养亏缺下，本地植物比根长、比根表面积及细根根长显著增加，根组织密度降低，变幅为8.23%~32.64%，而入侵植物变化不显著或呈相反趋势。水分亏缺普遍促进两类植物性状优化。综上，应对营养亏缺，入侵植物依赖高AMF侵染，本地植物则以根系形态调整为主；水分亏缺下两者根系策略相似，但入侵植物AMF侵染率更高；耦合胁迫响应类似于营养单胁迫。该研究揭示了入侵物种在资源胁迫下的适应机制，为解析其入侵性提供了依据。

关键词: 入侵植物, 水分亏缺, 营养亏缺, AMF, 根系形态特征