Effects of indigenous and exotic Rhizoglomus intraradices strains on trifoliate orange seedlings.
Background and Objective: Citrus plants are widely cultivated in tropical and subtropical countries and strongly depend on arbuscular mycorrhizal symbiosis. The present work was to evaluate the effect of indigenous and exotic Rhizoglomus intraradices strains on trifoliate orange for comparing the capacity of mycorrhizal fungi in citriculture. Materials and Methods: Two ecologic R. intraradices strains from China (indigenous) and Canada (exotic) were inoculated into potted trifoliate orange for 130 days. The root mycorrhizal colonization, root morphological traits, plant growth performance, soil glomalin concentrations, chlorophyll concentration and tissue nutrient levels were measured. Results: Mycorrhizal plants with indigenous R. intraradices strain had significantly higher root mycorrhizal colonization and entry points than those with exotic R. intraradices strain. Two R. intraradices strains collectively significantly increased plant growth performance, root morphology, chlorophyll concentrations and mineral nutrient levels compared with non-AMF treatments, whilst indigenous R. intraradices strain had superior effects than exotic R. intraradices strain. The AMF inoculation notably increased glomalin-related soil protein concentrations, whilst exotic R. intraradices strain had superior effects than indigenous R. intraradices strain. Conclusion: Indigenous R. intraradices strain conferred a superior role in trifoliate orange than exotic R. intraradices strain.