Enhancing cherry tomato performance under water deficit through microbial inoculation with Bacillus subtilis and Burkholderia seminalis

Abstract

Crop productivity can be affected by biotic and abiotic stressors, and plant growth promoting bacteria (PGPB) from the genera Bacillus and Burkholderia have the potential to maintain fruit yield and quality, as these bacteria can promote plant growth by solubilizing nutrients, fixing atmospheric nitrogen, producing phytohormones, and exhibiting antagonistic activity against pathogens. This study aimed to evaluate the effects of inoculating plants with Bacillus subtilis and Burkholderia seminalis on their morphological characteristics, fruit technological attributes and yield of common cherry tomatoes (Solanum lycopersicum L.) subjected to induced water deficit. The study was arranged on a split-plot randomized block design, with four water replacement levels (40%, 60%, 80% and 100% of crop evapotranspiration, ETc) and three inoculation treatments (Bacillus subtilis ATCC 23858, Burkholderia seminalis TC3.4.2R3 and non-inoculation). Data were subjected to analysis of variance using the F-test and compared using Tukey’s test (p < 0.05) and multivariate statistics from principal component analysis. Inoculation with Burkholderia seminalis increased the plant fresh and dry shoot and root mass, as well as root volume. Inoculation with Bacillus subtilis increased carotenoid and chlorophyll b contents. Both inoculations enhanced leaf water content in plants experiencing severe water deficit (40% of ETc). The use of these strains as PGPB increased the fruit soluble solids content. Higher productivity in inoculated plants was achieved through a greater number of fruits per cluster, despite the individual fruits being lighter. Treatments with higher water replacement levels resulted in greater yield. Inoculations showed biotechnological potential in mitigating water deficit in cherry tomatoes.