Eficiência de Gluconacetobacter diazotrophicus no aumento da tolerância de arroz vermelho à deficiência hídrica durante a fase reprodutiva

• Ano de defesa: 2015
• Autor(a) principal: Filgueiras, Luanna Maria Beserra
• Orientador(a): Meneses, Carlos Henrique Salvino Gadelha
• Banca de defesa: Silva, Silvanda de Melo , Maia, Josemir Moura
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual da Paraíba
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ciências Agrárias - PPGCA
• Departamento: Pró-Reitoria de Pós-Graduação e Pesquisa - PRPGP
• País: BR
• Palavras-chave em Português: Oryza sativa L; Bactéria endofitica diazotrófica; Telerância ao estresse hídrico; Mitigação do estresse
• Palavras-chave em Inglês: Water stress tolerance; Endophytic diazotrophic bacteria; Stress mitigation
• Área do conhecimento CNPq: CIENCIAS AGRARIAS
• Link de acesso: https://repositorio.uepb.edu.br/handle/123456789/75371

Despite being virtually unknown to most Brazilians, red rice has been mainly grown by small farmers in the Brazilian Northeast, having great economic and social importance. The use of plant growth promoting bacteria can be a viable alternative to assist in the development of plants under stress conditions through the production of phytohormones and biological nitrogen fixation, which act to reduce the negative effects that stress can cause in the development of the plants. Therefore, the aim of this study was to evaluat growth, ecophysiological, biochemical and productive aspects of red rice plants inoculated with Gluconacetobacter diazotrophicus under water stress. The experiment was carried out with the red rice cultivation (genotype 405 EMBRAPA Meio Norte) inoculated with G. diazotrophicus and not inoculated with and without water restriction. A completely randomized design was used with 8 treatments and 4 replications, where each plot consisted of a lysimeter containing 60 plants. We evaluated growth variables (plant height, leaf area, biomass), ecophysiological variables (gas exchange and chlorophyll a fluorescence), biochemical variables (photosynthetic pigments, proline, glycine betaine and MDA) and production variables (number of panicles per plant, dry matter of 1000 grains and total mass production). Inoculated and unnon-inoculated red rice under different water contents in the soil (70%, 50% and 30%) showed variation in all variables, except for Y(NPQ). During water restriction increases were observed in proline, glycine betaine, internal carbon concentration (Ci), intrinsic water use efficiency (EiUA) and quantum yield of unregulated dissipation (Y(NO)) levels. After rehydration these values were reduced in the inoculated plants. The malondialdehyde (MDA) showed better results in non-inoculated plants. Productive components, such as weight of 1000 grains, panicle number per plant and total mass were also significant for the inoculated rice. Therefore, the inoculation with G. diazotrophicus, proved to be a potential tool to reduce water stress in red rice.