Longevidade de sementes de arroz e de biótipos vermelho e preto no solo

• Ano de defesa: 2011
• Autor(a) principal: Amato, Ana Laura Pereira
• Orientador(a): Maia, Manoel de Souza
• 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 Ciência e Tecnologia de Sementes
• Departamento: Faculdade de Agronomia Eliseu Maciel
• País: BR
• Palavras-chave em Português: Oryza sativa; Banco de sementes; Viabilidade; Dormência
• Palavras-chave em Inglês: Oryza sativa; Seed bank; Viability; Dormancy
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::PRODUCAO E BENEFICIAMENTO DE SEMENTES
• Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/1514

RACT. The objective was to evaluate seed longevity of rice cultivars, strawhull (SH) and blackhull (BH) biotypes in soil seed bank of the main rice production area of Uruguay. Longevity of seeds buried in June 1993 was evaluated in two experiments: - experiment 1 (EXP1) with seeds of the rice cultivars El Paso 144, INIA Tacuarí and EEA 404; - experiment 2 (EXP2) with seeds of SH and BH. A split-plot experimental design was used with three replications in both experiments, were burial depths of 5 or 15 cm treatments were located in the big plots. In EXP1, burial time treatments of 10years for El Paso 144 and 5 years for INIA Tacuarí and EEA 404 were located in the subplots, where cultivars were considered as subsubplots. In EXP2, biotypes treatments were located in the subplots and buried for 20 years. Each treatment consisted of 200 seeds buried in PVC open cylinders. Seeds were exhumed for the first time in September 1993, after three months of burial. After that, seeds were exhumed on the same date each year until no viable seeds were found. Exhumed seeds were classified for viability and dormancy by germination and tetrazolium tests. SH and BH biotypes seed samples were classified for percentage of viable seeds, dead seeds, glumes and non identified loses. Data were analyzed using the SAS general linear model (GLM) procedures. Means were compared using the Tukey test (p<0.05). Maximum viability for rice cultivar seeds was registered as three years for El Paso 144. Differences were observed in seed viability according to cultivar. At three months of burial, Japonica cultivars had lost more than 80% of seed viability, while Indica cultivars had lost less than 50% of seed viability, as an average of both depths. SH and BH biotypes showed long viability, up to 12yr for SH and 11yr for BH; showing higher seed viability at 15 cm of burial depth than at 5 cm. SH showed longer viability than BH for both burial depths.