Photosynthetic activity and growth of poblano pepper biofertilized with plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi

The rhizosphere of plants are natural hosts for beneficial microorganisms such as plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF). The objective of this work was to determine the effect of a consortium of AMF and three strains of PGPR on growth, gas exchange and phosphorus content in poblano pepper plants. An experiment was established in a completely randomized design with factorial arrangement, with two factors: AMF [Funneliformis geosporum and Claroideoglomus sp. (AM) and without AM (WM)] and PGPR [Rhizobium nepotum (B1), Serratia plymuthica (B2), Pseudomonas tolaasii (B3) and without PGPR (WB)]; generating eight treatments: T1) AM+B1, T2) AM+B2, T3) AM+B3, T4) AM+WB, T5) WM+B1, T6) WM+B2, T7) WM+B3 and T8) WM+WB. Plant height, number of leaves, leaf area, number of flowers, dry biomass, phosphorus content and AMF colonization were measured; internal CO₂ concentration (Ci), transpiration rate (E), stomatal conductance (gS) and photosynthesis rate (Pn) were determined in leaves. Co-inoculation with AM+B3 promoted greater height (35%), number of leaves (66%), leaf area (62%), dry biomass (140%), phosphorus content (195%) and mycorrhizal colonization (26%); AM+B2 improved Ci (5%), E (8%), gS (5%) and Pn (9%) in poblano pepper leaves, compared to the control treatment (WM+WB). Biofertilization with AMF and PGPR improved gas exchange and growth of poblano pepper.