Abstract

The use of salinity-tolerant symbiotic plants to rehabilitate salt-affected lands is practiced in many areas in the world, but is often faced with the survival of introduced plants in their new environments. However, plant vitality could be improved by inoculation with symbiotic rhizobia and arbuscular mycorrhizal fungi (AMF), known to make available essential plant nutrients such as nitrogen and phosphorus. Vachellia nilotica subspecies Adansonii, a symbiotic legume and excellent candidate for the rehabilitation of degraded soils. The present study aimed to assess the effect of rhizobia and AMF inoculation on V. nilotica species adansonii plants' growth improvement and salinity tolerance. A greenhouse experiment was carried out with inoculated treatments with AMF (Rhizoglomus and Gigaspora species) combined or not with rhizobia (Mesorhizobium, Rhizobiun and Sinorhizobium). Three levels of salinity were considered (0.250, and 500 mM). Nodulation, mycorrhization, plant growth parameters, and shoot mineral content were assessed. Results showed that salinity negatively affected these parameters. However, combined AMF/rhizobia improved them in inoculated plants under salinity. Globally, inoculation with Rhizoglomus and Mesorhizobium improves mycorrhization, nodulation, and biomass. Also, inoculated plants showed more nitrogen (N), Phosphorus (P) and Sodium (Na) content at high salinity. Sodium-potassium (K/Na) ratio decreases with salinity and was higher in Rhizoglomus/Mesorhobium treatment at 500 mM

Key words: Vachellia nilotica, arbuscular mycorrhizal fungi (AMF), salt tolerant rhizobia, inoculation, symbiotic parameters, salinity.