Arbuscular mycorrhizal fungi increase the bioavailability and wheat (Triticum aestivum L.) uptake of selenium in soil

The interaction between arbuscular mycorrhizal (AM) fungi and selenium (Se) bioavailability in rhizosphere soils of host plants is still unclear. Pot trials were conducted to investigate the effects of inoculation of AM fungi on Se uptake in winter wheat growing on selenite (Se (IV)) or selenate (Se (VI)) spiked soils (2.5 mg kg(-1)) and on Se bioavailability in the rhizosphere soils. Inoculation of Funneliformis mosseae (F.m) and Glomus versiforme (G.v) significantly (P < 0.05) increased concentration of available Se (SOL-Se or EXC-Se) in the rhizosphere soils by 30.21 %-189.19 % and 12.03 %-76.35 % in Se (IV)- or Se (VI)- spiked soils, and the effect of inoculatingF.m was better than G.v. Se content in winter wheat was significantly (P < 0.05) enhanced by 24.11-56.06 % and 20.27-56.49 % in Se (IV)- or Se (VI)- spiked soils inoculated with F.m and G.v. The present results also showed that Se availability in rhizosphere soils of wheat was apparently influenced by speciation of exogenous Se. In addition, correlation analysis showed that soil organic matter (SOM), dissolved organic carbon (DOC), easily extractable glomalin-related soil protein (EE-GRSP), fungi and actinomyces abundance were significantly positively correlated with available Se in the rhizosphere soils, while were negatively correlated with pH. The present study indicated that inoculation of AM fungi could increase Se bioavailability in the rhizosphere soils via influencing partial soil chemical properties including pH, SOM, DOC, EE-GASP and microbial quantities, consequently enhancing Se uptake in winter wheat. This study can provide a theoretical basis for the study of AM fungi on Se biofortification of winter wheat.