Effects of arbuscular mycorrhizal fungi inoculation and phosphorus application on maize growth under vanadium stress.

Vanadium (V) and phosphorus (P) are similar in chemical structure. Arbuscular mycorrhizal fungi (AMF) have high affinity for P. To investigate the effects of AMF inoculation and P application on maize growth under V stress, we investigated the effects of AMF inoculation and P application (0, 20 and 50 mg·kg^-1 P₂O₅) on maize growth, P and V uptake, and V speciation in the soil amended with four levels of V addition (0, 100, 200, and 400 mg·kg^-1 V). The results showed that V stress (100, 200 and 400 mg·kg^-1) significantly decreased root mycorrhizal colonization and plant biomass. The 200 and 400 mg·kg^-1 V stress treatments significantly decreased root mycorrhizal colonization by 14.9%-28.0% and 29.5%-31.9%, and reduced plant biomass by 41.4%-42.2% and 54.3%-55.3%, respectively. V stress significantly decreased P concentration and uptake of maize shoot and increased V concentration and uptake of maize shoot and root. AMF inoculation and P application could alleviate the inhibition effect of V on maize growth, which significantly decreased bioconcentration factor of V by 23.3%-47.7% and translocation factor of V by 13.1%-27.9%, as well as V concentration and uptake of maize shoot, but improved plant biomass and P uptake of maize shoot and root. The factor of AMF inoculation and P application had interaction on root mycorrhizal colonization and plant biomass, as well as P and V uptake of maize shoot. AMF inoculation promoted the reduction of V_V into V_IV in plant tissues. AMF inoculation could alleviate V stress by promoting maize growth and P uptake and inhibiting V translocation, with synergistic effects from P application.