Biotização com bactérias promotoras de crescimento na micropropagação do morangueiro e caracterização da comunidade microbiana endofítica

Abstract

Strawberry (Fragaria × ananassa) is a globally important crop, and its production can be achieved through in vitro micropropagation. This technique enables the generation of microplants from a mother plant under aseptic conditions, followed by transplantation to ex vitro conditions, a crucial stage for survival. This study evaluated the effect of ten plant growth- promoting bacteria (PGPB) on biotization during in vitro micropropagation and ex vitro acclimatization, as well as characterized the endophytic bacterial community in strawberry plants across three generations of the San Andreas cultivar. The genera Bacillus, Azospirillum, and Rhizobium stood out due to their ability to fix nitrogen, solubilize phosphate and potassium, and produce hydrolytic enzymes, having beneficial effects on biotization. Additionally, ex vitro re-inoculation induced physiological and biochemical modulations in the plants. Characterization of the endophytic community revealed a reduction in phylum diversity throughout in vitro cultivation, with a predominance of the phylum Actinobacteriota. In contrast, the mother plant exhibited greater microbial diversity, with a predominance of the phyla Firmicutes, Actinobacteriota, and Proteobacteria, highlighting changes in the bacterial microbiome during the micropropagation process. Thus, biotization with plant growth- promoting bacteria emerges as a promising strategy for restoring and replenishing the microbiota of in vitro-cultivated microplants, potentially enhancing their adaptation to ex vitro conditions. Therefore, the individual or consortium application of these bacteria could reduce dependence on chemical fertilizers and promote more sustainable agriculture.