Changes in yield and quality features of sweet pepper as modulated by arbuscular mycorrhizal fungi and molybdenum biofortification

Arbuscular mycorrhiza (AM) are obligate symbionts between roots of higher plants and fungi belonging to the monophyletic phylum Glomeromycota. AM elicit nutrients absorption and efficiency, improving yield and quality of vegetables under optimal, sub-optimal or non-optimal growing conditions. Molybdenum (Mo) is an essential trace element to face human illnesses linked to the sulphite oxidase simple deficiency. The goal of the current study was to evaluate the effect of the AM fungi (Glomus intraradices) and different doses of Mo (0, 0.5, 3 or 6 mu mol L-1) on yield, nutritional and nutraceutical traits of 'Golden Italian SS' F-1 sweet pepper grown in a protected environment. AM and a Mo dosage of 3.0 mu mol L-1 significantly enhanced mycorrhizal colonization, total yield, marketable yield and marketable fruit number compared with the control. Regardless of the AM application, Mo-biofortification at 0.5 or 3.0 mu mol L-1 boosted mean mass of marketable fruits. Plants not inoculated with AM and biofortified with 6.0 mu mol Mo L-1 showed a significant increase in terms of soluble solid content and total phenolics. AM fungi enhanced ascorbic acid concentration. Furthermore, ascorbic acid fruit concentration augmented as Mo concentration in the nutrient solution increased. The highest Mo fruit concentration was found in fruits from the +AM x 6.0 combination. Whereas, the lowest Mo concentration was found in fruits from non-biofortified plants. Our data pointed out that AM fungi and Mo-biofortification, with a dosage of 0.5 or 3.0 mu mol Mo L-1 significantly ameliorate crop production and quality of 'Golden Italian SS' sweet pepper. The study also suggests that AM fungi had a buffer action on sweet pepper Mo harmfulness.