Potential use of rhizobacteria from theBacillusgenus to stimulate the plant growth of micropropagated bananas

Abstract

Introduction . Soil microbiota communities have demonstrated their crucial role in maintaining the soil ecological balance and therefore the sustainability of either natural ecosystems or agroecosystems. Rhizospheric microbe-plant interactions have a great influence on plant health and soil quality since these root-associated microorganisms are able to help the host plant to deal with drought, nutritional and soil-borne pathogen stress conditions. Plant growth-promoting rhizobacteria (PGPR) can be considered among rhizosphere-beneficial microorganisms. In a micropropagated plant system, bacterial inoculation at the beginning of the acclimatisation phase must also be observed from the perspective of the establishment of the soil microbiota rhizosphere. The objective of this work was to evaluate the effect of a rhizobacteria consortium of Bacillus spp. on the first developmental stages of two micropropagated bananas. Materials and methods . Two varieties of banana plant cultivars (‘Grande Naine’ and a banana-derived tetraploid hybrid ‘ITC 1297’) were inoculated or not with a suspension of Bacillus spp. at the beginning of the weaning phase. Six plants were considered per treatment and cultured under greenhouse conditions in a randomised design. For both cultivars, plants were harvested (135 and 185) days after bacterial inoculation and analysed for growth parameters and nutrient contents. Results . Concerning plant development, bacterial application induced a positive effect on both cultivars although this effect showed some time differences depending on the banana cultivar. Foliar mineral contents were significantly increased only in ‘Grande Naine’ plants at 135 days. Our results demonstrated for the first time that the Bacillus spp. consortium tested was able to improve banana development (both cultivars) and foliar mineral contents in one of them. Conclusion . Therefore, this bacterial consortium can be described as PGPR for banana under these experimental conditions. This biotechnology, adaptable to the hardening phase, thus represents a prospective way to increase plant health and survival rates in commercial nurseries.