EVALUATION OF DIFFERENT METHODS OF INOCULATION WITH NATIVE RHIZOBACTERIA ON TOMATO CROPS AND ITS EFFECT ON AGRONOMICAL AND NUTRITIONAL PARAMETERS

ALMIRÓN, C.C.; BADIN, E.E.; BODOIRA, R.M.; RIBOTTA, P.D.; ARECO, V.A.; PONSO, M.A.; ROMERO, A.M.; LESPINARD, A.R.; YARYURA, P.M.

Los Cocos, Córdoba

Congreso; XVII Congreso Argentino de Microbiología General; 2022

Sociedad Argentina de Microbiología General-SAMIGE

Plant growth promoting rhizobacteria (PGPR) is considered an important alternative for partial or total substitutions of chemical fertilizer, which are currently highly overused in tomato (Solanum lycopersicum) crop production. Tomato is one of most widely consumed vegetable in the world and also one of the most nutritious, due to its composition rich in bioactive compounds, mainly lycopene and antioxidants. Nowadays, there is a growing demand for food produced in a sustainable manner and with a high nutritional quality, for these reasons it is important to find new production alternatives. The aims of this work were first to evaluate the impact of five native rhizobacteria (VMAP2, VM4, VMYP6, VMY10 and VMY15) isolated from tomato plants rhizosphere, using three inoculations methods on vegetative tomato growth, and then to select the PGPRs strain and inoculation method that allow obtaining a higher yield and a better nutritional quality of tomato fruit. The tests were organized as follows: [A] inoculation in seed and 30 days after sowing (DAS) evaluate the following traits: root length, shoot length, leaves area, shoot, root and plant dry weight (SDW; RDW and PDW, respectively), germination percentage (G%), relative growth of shoot (RGS), relative growth of root (RGR) and vigor index (VI). [B] selection of the best strains evaluated previously to be later inoculated in seed (S), in seed and root (S+R) and root only (R) for determination at 75 DAS, traits associated with promoting plant growth such as root length, RDW, SDW, leaves dry weight (LDW) and leaves area. [C] to evaluate the best methodology of inoculation on crop reproductive stage (150 DAS) to determined number of flowers, red fruit yield and means of fruit nutritional and sensory attributes (lycopene and ascorbic acid concentration, physical-chemistry and colorimeter parameters). Data from experiment were analyzed by ANOVA (P≤0.05 LSD Fisher). [A] The result showed that TVMY15 and VMYP6 significantly increased RGS and RGR, while VMY10 increased the values of RGR only. The VI was significantly incremented with the inoculation of VMY15. For [B] it was observed that strain VMYP6, VMY10 and VMY15 produced significant increases with respect to other inoculation methodologies and to the control in root length, RDW, LDW, SDW and leaves area when root inoculation methodology was applied. For [C] it was observed that root inoculation with VMY15 incremented the number of flowers with respect to the control. Lycopene content in tomato fruits increased significantly with respect to the uninoculated control for all treatments with bacterial inoculations, while ascorbic acid was only increased for VMY15 and VMYP6. This work shows that root inoculation with native rhizobacteria is a sustainable strategy for reducing chemical fertilizer for tomato crop management to guarantee safety and nutritional quality.