The aim of this work was to evaluate the influence of P levels and arbuscular mycorrhizal fungi (AMF) on growth and mineral nutrition of Citrus limonia. The experiment was conducted under greenhouse conditions, with a completely randomized 6 x 3 factorial design, with six P levels (0, 50, 100, 150, 200 and 250 mg kg-1 of substrate), two species of AMF (G. etunicatum and G. intraradices) and a control without AMF, with three replicates per treatment, using 1.7 dm-3 pots. Five months after transplanting, plants were assessed for height, stem diameter, shoot dry matter, shoot nutrient content, root colonization and substrate analysis for active (AEM) and total (TEM) extraradical AMF mycelium length. Citrus limonia presented high mycorrhizal dependence on nutrient absorption, mainly when inoculated with Glomus intraradices, which promoted greater plant height, larger stem diameter and greater shoot dry matter production. Only G. intraradices promoted detectable root colonization, with percent root colonization being inversely proportional to the applied P level. AEM and TEM increased in accordance with P levels, and high correlations were found between the former and nutrient absorption. Although no root colonization could be observed, G. etunicatum produced AEM and TEM, which may show a saprophytic capacity for survival in soil.
citrus; extraradicular mycelium; Glumus intraradices