Valeria Todeschini
University of Piemonte Orientale, Italy
Title: Inoculation with soil beneficial microorganism improve fruit quality and production in strawberry plant
Biography
Biography: Valeria Todeschini
Abstract
Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth Promoting Bacteria (PGPB) are soil beneficial microorganisms strictly associated with plant roots, able to improve plant growth. The interaction between plants and AMF and/or PGPB can also affect plant metabolism, increasing photosynthetic rate and the production of the so-called healthy compounds.
In this study, three different AMF (Funneliformis mosseae, Septoglomus viscosum, Rhizophagus irregularis) were used in combination with three different strains of PGPB (19Fv1t, 5vm1K, Pf4) to inoculate plantlets of Fragaria x ananassa Duch var. Eliana F1 in order to investigate the effects of different AMF/PGPB combinations both on plant growth and fruit quality. The plants, grown in a greenhouse for 4 months, were irrigated with nutrient solution at two different level of phosphate: half of the control uninoculated plants (C) was fed with 32µM phosphate, while the remaining controls (C-P) and all the inoculated ones were fed with 16µM phosphate. The number of newly produced flowers and fruits was recorded weekly. Mature fruits were harvested, weighted, measured and used for biochemical analyses. At harvest, fresh and dry weights of roots and shoots, mycorrhizal colonization (M%) and content of leaf photosynthetic pigments were measured. Moreover, the following fruit parameters were recorded: pH, titratable acids, concentration of organic acids, sugars, vitamin C and anthocyanidins. Volatile profile and elemental composition in fruits were also evaluated. Data were statistically analyzed by one-way and two-way ANOVA. Moreover, principal component analysis (PCA) and PCA-DA (discriminant analysis) were used to draw a general profile of strawberry plants through the different considered variables.
AMF/PGPB combinations differently affected plant growth parameters, increasing root and shoot biomass and the concentration of photosynthetic pigments. Plants inoculated with R. irregularis showed the highest M% (20-30%). Co-inoculation also improved plant growth, fruit yield and quality: plants inoculated with Pf4, regardless of its combination with the used fungus, showed a higher number of flowers and fruits produced per plant, an increase of malic acid concentration and a decrease of pH in the fruits, if compared to the other treatments. The PCA-DA analysis reveal that the presence of a specific fungus and/or bacterium in the soil determined the production of specific compounds in fruits: volatile profile and elemental composition observed for each treatment were different from the other ones, underlining the uniqueness of strawberry flavour, aroma and odor of each treatment. In general, the factor “fungus” mostly affected the parameters associated with the vegetative portion of the plant, while the factor “bacterium” was more relevant for fruit yield and quality