Effect of Selenium Biofortification and Beneficial Microorganism Inoculation on Yield, Quality and Antioxidant Properties of Shallot Bulbs

Abstract

Plant biofortification with selenium in interaction with the application of an arbuscular mycorrhizal fungi (AMF)-based formulate,with the goal of enhancing Se bioavailability, is beneficial for the development of the environmentally friendly production of functional food with a high content of this microelement. Research was carried out in order to assess the effects of an AMF-based formulate and a non-inoculated control in factorial combination with two selenium treatments with an organic (selenocystine) or inorganic form (sodium selenate) and a non-treated control on the yield, quality, antioxidant properties, and elemental composition of shallot (Allium cepa L. Aggregatum group). Selenocystine showed the best effect on the growth and yield of mycorrhized plants, whereas sodium selenate was the most effective on the non-inoculated plants. The soluble solids, total sugars, monosaccharides, titratable acidity, and proteins attained higher values upon AMF inoculation. Sodium selenate resulted in higher soluble solids, total sugars and monosaccharide content, and titratable acidity than the non-treated control, and it also resulted in higher monosaccharides when compared to selenocystine; the latter showed higher protein content than the control. Calcium, Na, S, and Cl bulb concentrations were higher in the plants inoculated with the beneficial microorganisms. Calcium and sodium concentrations were higher in the bulbs of plants treated with both the selenium forms than in the control. Selenocystine-treated plants showed enhanced accumulation of sulfur and chlorine compared to the untreated plants. The AMF inoculation increased the bulb selenium content by 530%, and the Se biofortification with selenocystine and sodium selenate increased this value by 36% and 21%, respectively, compared to control plants. The AMF-based formulate led to increases in ascorbic acid and antioxidant activity when compared to the non-inoculated control. The bulb ascorbic acid was increased by fortification with both selenium forms when compared to the non-treated control. The results of our investigation showed that both AMF and selenium application represent environmentally friendly strategies to enhance the overall yield and quality performances of shallot bulbs, as well as their selenium content.

Tomato Yield, Quality, Mineral Composition and Antioxidants as Affected by Beneficial Microorganisms Under Soil Salinity Induced by Balanced Nutrient Solutions

“…Consistently with our findings, in previous research [18] a higher dry residue was recorded in tomato fruits harvested from plants co-inoculated with AMF and Pseudomonas sp. The increase of soluble solids but not of dry residue was recorded in shallot bulbs upon the application of a mixed beneficial microorganism formulate [55]. Contrastingly to the results of the present investigation, Candido et al [40] did not record significant differences between AMF-inoculated and control plants in terms of tomato fruit dry weight and soluble solids.…”

Yield, Essential Oil and Quality Performances of Artemisia dracunculus, Hyssopus officinalis and Lavandula angustifolia as Affected by Arbuscular Mycorrhizal Fungi under Organic Management

“…Indeed, in the latter crop the beneficial microorganisms did not lead to yield and plant biomass increase, contrary to what was recorded in Artemisia dracunculus and Hyssopus officinalis (Table 1). In previous research carried out on shallot [26], onion and garlic [18] and tomato [27], AMF inoculation resulted in higher root mycorrhizal colonization percentages than those recorded in the present investigation. The data presented in Figure 1 indicate different effects of AMF preparation on phenological phases of aromatic plant development.…”

“…The reduced concentration of Se in AMF-inoculated lavender compared to control plants, contrary to A. dracunculus and H. officinalis, suggests that AMF application may species-dependently enhance the concentration of this essential element to human beings. Previously, the beneficial effect of AMF inoculation on Se accumulation in garlic, onion and shallot bulbs was reported [18,26]. Lavender showed a remarkable increase in Cr, Li and Zn content.…”

Hydroponic Production of Reduced-Potassium Swiss Chard and Spinach: A Feasible Agronomic Approach to Tailoring Vegetables for Chronic Kidney Disease Patients

“…A novel challenge in agriculture is the production of tailored foods, i.e., foods specifically suitable for target groups of people with particular nutritional needs. In fact, in recent years, a number of studies have highlighted the possibility of producing vegetables for specific physiological conditions, such as biofortified vegetables, with the aim of counteracting different nutritional deficits [1][2][3][4][5][6][7][8]. In general, these authors reported evidence on the use of specific growing protocols aimed to increase the content of specific nutrients in plant tissues, such as iodine (I), silicon (Si), calcium (Ca), selenium (Se), zinc (Zn), and iron (Fe).…”