Bacteria associated to the roots of Phaseolus vulgaris L. at different development stages: diversity and plant growth promotion

• Autor(a) principal: Rocha, Ricardo Alexandre
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/33366
• topic: Plant growth promoting bacteria; Rhizobacteria diversity; Plant life cycle; Vegetative growth; Reproductive growth; Growth promoting traits; Idole acetic acid; Siderophores; Antifungal capacity

World population is increasing, and it is expected that this increase will impose a major pressure on food production. The present methodologies of agricultural production are vulnerable to the unstable climate that is predicted to increase, in addition to other growing pressures such as increasing urbanization, industrialization, and agrochemical pollution. As a result, agricultural production needs to be increased, for achieving food security and meet the sustainable development goals formulated by the United Nations. The common bean (Phaseolus vulgaris L.) is one of the most produced legumes worldwide and, as a good source of reliable protein, can help reduce the environmental impact (e.g, CO2 and CH4) generated in the process of meat production and at the same time increase the nutritional level of the population in developing countries. Plant growth promoting rhizobacteria are emerging as a possibility to help increase agricultural production, since their interaction with plants promote development, growth, and protection of plants in several ways. This thesis was developed to help clarifying the dynamics between plants and microorganisms resulting in plant growth promotion throughout plant life cycle. For that, cultivable microbiome was isolated and identified at different stages of plant development (early vegetative growth, late vegetative growth, flowering, and pod) and root compartments (outside, inside and nodules). Results validated variation in diversity and abundance of bacteria associated to root compartments throughout plant life cycle. Plant growth promoting abilities (indole acetic acid, siderophores production, and antifungal activity) of the isolated bacteria were also determined in root compartments at each stage of development stage. Significant differences in tested parameters were observed, demonstrating that the compounds promoting growth and protection provided by the microbiome were specific to a given time of plant development. The results obtained showed the potential of PGPR to assist plant growth, while allowing the reduction of chemical fertilizers and fungicide application, becoming a turning point in agricultural production by making the food production more sustainable and greener.