Caracterização morfofenológica e molecular de mutantes de arroz irrigado

• Ano de defesa: 2013
• Autor(a) principal: Silva, Aline Scheer da
• Orientador(a): Peters, José Antônio
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Fisiologia Vegetal
• Departamento: Biologia
• País: BR
• Palavras-chave em Português: Oryza sativa L.; Variabilidade genética; Raios gama; Caracteres agronômicos e AFLP
• Palavras-chave em Inglês: Oryza sativa L.; Genetic variability; Gamma rays; The agronomic characters and AFLP
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL
• Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/2004

Irrigated rice (Oryza sativa L.) presents a great economic and social importance, mainly in Brazil s southern region, which stimulates the search for more productive cultivars and with agronomic characteristics that meet market requirements. Support techniques to improvement programs, as induced mutations and use of molecular markers, are being increasingly used. Induced mutations are considered to be an alternative method in order to create genetic variability, being the use of ionizing radiation an effective technology with which mutants were obtained with characteristics of higher productivity, precocity, smaller, higher resistance to disease and pest infestation in different species, which are used in improvement programs to obtain new cultivars. AFLP is one of the most used molecular markers techniques to analyze genetic divergence in plant populations, mainly in species that present low rate of poliforfism in the DNA. The aim of this work was morphophenological and molecular characterization of mutants of rice derived from the BRS Querência and BRS Fronteira elite cultivars, which can turn into new cultivars or serve to crossings in rice breeding programs. In the 2009/2010 growing season, seeds of M1 plants (originated from seeds exposed to different doses of gamma radiation) were sown in trays containing soil typically found in rice culture, aiming seedling production. From two to three leaves, seedlings were transplanted to the field forming M2 population. In this generation, 59 mutants with agronomic characteristics of interest were selected. In the following growing season (2010/2011), seeds of these 59 mutant plants were sown and transplanted in the same previous conditions and formed M3 population. In all generations, morphophenologic descriptors of rice culture were evaluated. Genetic divergence among the mutant selected in generation M3 and the cultivar witnesses through the AFLP technique were also evaluated. The obtained data were submitted to analysis of variance, compared by means test (Dunnett) to 5% of probability. Multivariate analysis through GENES software were also performed (CRUZ, 2007). In both cultivars, mutants with characteristics of agronomic concern were obtained, such as reduction in culture cycle and in height of the plants, increase in thickness of the stem, greater tillering and panicle number, higher number of grains per panicle and higher 1000-grain weight. AFLP technique showed up to 51% dissimilarity among genotypes of the same origin, being M_CTT/ E_AAC the most informative primer combinations among the 13 combinations tested in this study. Based on the results that were obtained we conclude that some of the mutants obtained can be used in the future for gene action studies, crossings and/or to launch a new cultivar.