Bacterial microbiota associated with tomato (Solanum lycopersicum L.) plants var. elpida

In Argentina, tomato cultivation is the second most produced horticultural crop and ranks first among vegetables grown under cover in greenhouses, concentrating its production mainly in the La Plata Horticultural Belt. This is a crop with considerable nutritional requirements that are normally supplied by chemical fertilizers, in addition to the common treatment with phytosanitary products since they present numerous pests and diseases. In recent years, the accelerated process of soil degradation due to the implementation of intensive agricultural practices has led to a need for research and development of more sustainable practices. Taking into account that plants are naturally colonized by bacterial communities located in the rhizosphere, phyllosphere and endosphere, and that many of these bacteria play crucial roles in the health and growth of plants, interest was focused on the knowledge of the bacterial microbiota associated with tomato cultivation with the general objective of being able to take advantage of its ecosystem services to provide sustainable solutions to current agricultural challenges. There is still little information regarding the microbiota of both aerial and underground organs as well as the rhizosphere and soil associated with tomato plants grown in the CHP under production conditions, particularly var. elpida (variety used by producers in the region), which was of interest as a model plant for the ecological and bioprospecting study of the associated bacterial communities, using dependent and independent cultivation techniques (molecular).The results provided a complete and detailed characterization of the bacterial communities associated with the rhizosphere and endosphere of the root, stem and fruit of elpida variety tomato plants, finding that the abundance, structure, composition and functionality of the associated bacterial communities had as their main determinant to the microhabitat. The continuous agricultural practices commonly used in the horticultural activity of the CHP (refined tillage, chemical fertilization/fertigation, use of agrochemicals, organic amendments, monoculture) had both negative and positive impacts on the physical-chemical characteristics of the soil, the combined result of which was not resulted in the modification of emergent properties, but also in the change in the taxonomic profiles of the soil and rhizosphere bacterial communities. Furthermore, the changes in the soil and rhizosphere bacterial communities due to the effect of the site did not show modifications in the endosphere communities of plants grown in each of them, suggesting that tomato plants are a robust host of their endosphere bacterial communities. .On the other hand, bioprospecting studies showed that tomato plants are a natural reservoir of various cultivable bacteria, many of which could be isolated and characterized, exhibiting multiple PGPB traits: the selected bacterial isolates demonstrated their antagonistic and growth-promoting effect. plant in in vivo tests.