Aspectos nutricionais em ora-pro-nobis (Pereskia aculeata Mill.) relacionados a micro-organismos promotores de crescimento vegetal e características químicas e físicas do solo

• Ano de defesa: 2018
• Autor(a) principal: Vega, Cesar Florentino Puma
• Orientador(a): Moreira, Fatima Maria de Souza
• Banca de defesa: Pereira, Marcos Gervasio, Carvalho, Teotonio Soares de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Lavras
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência do Solo
• Departamento: Departamento de Ciência do Solo
• País: brasil
• Palavras-chave em Português: Plantas alimentícias não convencionais; Fixação biológica de nitrogênio; Ora-pro-nobis - Características físico-químicas; Fungos micorrízicos arbusculares; Unconventional food plants; Biological nitrogen fixation; Ora-pro-nobis - Physical-chemical characteristics
• Área do conhecimento CNPq: Ciência do Solo
• Link de acesso: https://repositorio.ufla.br/handle/1/32738

Ora-pro-nobis (OPN) is a sparsely cultivated horticultural cactus that presents high food potential due mainly to the high protein content in its leaves. However, little is known about the chemical, physical and biological characteristics of the soils where it occurs, as well as their relationships with their nutritional characteristics. Soil microorganisms play a key role in the life cycle of plants both in cycling and in the availability of nutrients. Bacteria are responsible for the biological fixation of nitrogen and other processes as promoters of plant growth of great agricultural and environmental relevance. Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with most vascular plants. This mycorrhizal association provides an increase in soil nutrient uptake by plants, mainly phosphorus, as a consequence of better soil exploration. The objective of this study was to evaluate the relationship of nutritional aspects of OPN with the communities of diazotrophic bacteria and arbuscular mycorrhizal fungi and chemical and physical characteristics of the soils in different places in the southern state of Minas Gerais. Soil, root and leaf samples were collected in four nearby municipalities located in rural and urban areas. Diazotrophic bacteria from soil, rhizosphere, and maceration of washed roots of OPN in water were isolated using the modified NFb semisolid medium. FMA spores were extracted from the soil by the wet sieving method followed by sucrose gradient centrifugation. The collected roots were discolored and analyzed according to the traditional methods for evaluation of mycorrhizal colonization. There was no relationship between the total nitrogen in the soil and the protein content in the OPN leaf. There was also no relationship between the content of the other macro and the micronutrients in the leaf and their corresponding contents in the soil except for the potassium. It was obtained 86 isolates distributed in 24 cultural groups. The partial sequencing of the 16S rRNA gene from the isolates identified the genus Azospirillum, of diazotrophic bacteria and to a lesser extent the genera: Azohydromonas, Azospira, Acinetobacter, Bacillus, Brevundimonas, Caulobacter, Cryseobacterium, Pseudomonas, Pseudoacidobacter and Variovorax. There was variation in spore density and mycorrhizal colonization. Despite the low root colonization of FMAs, there was considerable density of spores in the soil. The families Ambisporaceae, Archaeosporaceae, Claroideogloeraceae, Glomeraceae, Acaulosporaceae, Diversisporaceae and Gigasporaceae were identified. It is concluded that there are associative diazotrophic bacteria as well as AMFs in close relation with OPN which may be related to the high nitrogen content in the leaves of this plant species. The species of microorganisms found can be used in future selection studies aiming at the best OPN development.