Unravelling the effect of native arbuscular mycorrhizal fungi inoculation on onion plants growth, flower traits and pollinating insects interactions

• This study is the first to investigate the potential of Native arbuscular Mycorrhizal Fungi inoculation to improve onion plants growth, floral characteristics, nutrients and pollinating insects visitations. • The combined effects of AMF inoculation and organic fertilization has resulted in enhanced onion plants growth with improved floral morphology, and these effect has attracted more pollinating insects to the inoculated plants than the un-inoculated plants. • Foliar nutrients concentrations (Nitrogen, Phosphorous, Potassium) concentrations were also found to be higher in the inoculated plants than the un-inoculated plants. • Inoculated plants produced higher bulb number with enhanced seeds yield, which can be attributed to the positive effects of insects pollination and enhanced nutrient absorption of the plants. • Additionally the study highlighted strong positive correlations between onion plants floral characteristics, nutrients content and pollinating insects visitations. This study investigated the effects of inoculating onion plants with native arbuscular mycorrhizal fungi (AMF) strains on growth, nutrients uptake, flower parameters and the subsequent attraction of the flowers to pollinating insects. The inoculants were applied as single strains, T1 ( Septoglomus constrictum ), T2 ( Gigaspora margarita ), T3 ( Archaeospora trappei ) or in combinations: T4 ( S. constrictum + G. margarita ), T5 ( S. constrictum + A. trappei ), T6 ( G. margarita + A. trappei ), and T7 (a combination of all three strains), alongside control plants (T8). Among the treatments, T7 produced the most pronounced improvements, including the highest flower number (6.8), tallest flower stalks (112.96 cm), and largest umbel diameter (6.6 cm), whereas the control group exhibited the lowest values for these traits. Inoculated plants attracted more pollinators compared to controls, with T7 recording the highest visitation rates by Lepidoptera (33.4), Diptera (29.8), and Hymenoptera (35.4) during five-hour daily observation periods. Foliar nutrient analysis revealed that T5 plants had the highest nitrogen concentration (3.85 %), while T7 recorded the greatest phosphorus (1.10 %) and potassium (3.73 %) levels. Additionally, T7 produced the highest bulb count (8.0) and the greatest seed weights (9.76 g in T7 and 9.72 g in T4). These results highlighted the potential of native AMF inoculation to enhance flower production, increase pollinator attraction, and ultimately improve seed yield in onion cultivation under organic farming system.