Effect of Arbuscular Mycorrhizal Fungi on the Growth and Cadmium Uptake of Paspalum notatum and Lolium perenne

To investigate the regulatory mechanisms of arbuscular mycorrhizal fungi (AMF) on the growth, cadmium (Cd) uptake and translocation of plants with distinct mycorrhizal dependency (MD), a pot experiment was conducted using Paspalum notatum (high MD) and Lolium perenne (low MD) under two Cd gradients (5 mg·kg−1, 50 mg·kg−1) with AMF-inoculated/non-inoculated treatments, with 0 mg·kg−1 set as the control group. AMF significantly enhanced the dry weight and colonization rate of both plant species, and the MD of Paspalum notatum remained consistently higher. The growth-promoting effect of AMF (quantified by MD) exceeded the toxicity induced by Cd stress, thereby mitigating growth inhibition by promoting hyphal growth in the rhizosphere. AMF improved the root bioconcentration factor (BCF) and total Cd extraction capacity of the plants, which was correlated with the plants’ inherent Cd absorption capacity but not with MD. AMF exerted species-specific regulatory effects on the translocation factor (TF): the TF of Paspalum notatum increased after inoculation, while that of Lolium perenne decreased.