Abstract:

The successful invasion of alien plants is regulated by both abiotic factors (such as changes in aboveground and underground resources) and biological factors (such as mutualistic symbionts). In this study, the typical invasive plant Trifolium repens L. was used to investigate the effects of light, phosphorus, symbiotic arbuscular mycorrhizal fungi (AMF), and their interactions on growth using a three-factor two-level orthogonal experiment. Results showed that: (1) High light, high phosphorus, and AMF inoculation significantlyincreased the biomass and growth rate of T. repens. The promotion effect of AMF inoculation on biomass increased with increasing light, and the promotion effect of AMF on total biomass and relative growth rate was more pronounced under low phosphorus conditions; (2) High light intensity reduced specific leaf area but improved the performance of other aboveground traits, except for root mass fraction. High phosphorus and AMF inoculation significantly increased the number of leaves and total leaf area, which was more obvious under high light intensity; (3) High light intensity significantly increased root surface area, root diameter, and root mass fraction, but decreased the proportion of fine roots and specific root length. The promotion effect of high light intensity on root surface area was higher under low phosphorus. High phosphorus significantly reduced the root mass fraction. In the absence of AMF inoculation, high phosphorus increased the root surface area and root diameter and decreased the proportion of fine root length. However, after inoculation with AMF, high phosphorus reduced the root surface area and root diameter and also increased the proportion of fine root length. AMF significantly reduced the root mass fraction and specific root length. Overall, these results showed that light, phosphorus, and AMF significantly affected T. repens growth, and the intensity of the effects of phosphorus and AMF on growth and aboveground traits was dependent on light intensity, while the intensity of the effects of AMF on underground traits was dependent on phosphorus concentration.

摘要：

外来植物成功入侵受非生物因素与生物因素的共同调控。本研究以典型入侵植物白车轴草（Trifolium repens L.）为研究对象，通过三因素两水平正交实验，探究光照（L）、磷（P）和丛枝菌根真菌（Arbuscular mycorrhizal fungi，AMF）及其交互作用对其生长的影响。结果显示：（1）高光照、高磷和接种AMF均显著提高白车轴草的生物量及生长速率，且接种AMF对生物量的促进作用随着光照的增加而增强，低磷条件下AMF对总生物量和相对生长速率的促进效应更明显；（2）高光照降低比叶面积；高磷和接种AMF显著增加叶片数和总叶面积，在高光强下尤为明显；（3）高光照可显著提高根表面积、根直径和根质量分数，但降低细根占比和比根长。高磷显著降低根质量分数。不接种AMF时，高磷增加根表面积与根直径，降低细根长占比；但接种AMF后，高磷则降低根表面积与根直径，增加细根长占比。AMF显著降低根质量分数和比根长。研究结果表明，三种因素对白车轴草的生长具有显著影响，且磷和AMF对其生长及地上性状的影响与光照强度相关，AMF对其地下性状的影响与磷浓度相关。