Germinação de sementes de Stryphnodendron Mart. osmocondicionadas
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Data
2010-06-01
Autores
Kissmann, Camila [UNESP]
Scalon, Silvana de Paula Quintão
Mota, Leandro Henrique de Sousa
Vieira, Maria do Carmo
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Tecnologia de Sementes (ABRATES)
Resumo
Objetivou-se com esse trabalho avaliar a germinação de sementes de três espécies de Stryphnodendron Mart. (Stryphnodendron adstringens (Mart.) Coville, S. obovatum Benth. e S. polyphyllum Mart.) osmocondicionadas em diferentes agentes osmóticos, nos potenciais de -1.0 MPa e -0.5 MPa. Sementes escarificadas em ácido sulfúrico durante 40 minutos foram condicionadas nos seguintes tratamentos: 1) PEG 6000; 2) PEG 6000 + KNO3, em partes iguais; 3) KNO3; 4) Água e 5) Testemunha, e incubadas em câmara de germinação (BOD) na temperatura de 20 ºC (± 2 ºC) durante 0 h (controle), 6h, 12h e 24 horas, com luz contínua. Para cada espécie, o delineamento estatístico foi o inteiramente casualizado em esquema fatorial 5 (tratamentos de osmocondicionamento) x 4 (tempos de condicionamento) com quatro repetições de 20 sementes. Foram avaliados a porcentagem de germinação (%G), índice de velocidade de germinação (IVG), comprimento médio de raiz (CMR) e de parte aérea (CMPA), e massa fresca (MF) e seca (MS) das plântulas condicionadas a -1,0 MPa e, a %G e IVG daquelas condicionadas a -0,5 MPa. O osmocondicionamento no potencial de -1,0 MPa não alterou significativamente o desempenho fisiológico das sementes de S. obovatum e S. polyphyllum, mas foi prejudicial ao desenvolvimento de S. adstringens. O condicionamento das sementes de S. adstringens e S. polyphyllum em potencial de -0,5 MPa promove maior %G e IVG.
The objective of this study was to evaluate the germination of seeds of three species of Stryphnodendron Mart. (Stryphnodendron adstringens (Mart.) Coville, S. obovatum Benth. and S. polyphyllum Mart.) under priming in different osmotic agents, in osmotic potentials of -1.0 MPa and -0.5 MPa. Seeds scarified in concentrated sulphuric acid for 40 minutes were conditioned in the following treatments: 1) PEG 6000; 2) PEG 6000 + KNO3, in equal parts; 3) KNO3; 4) Water and 5) Control. Afterwards, they were incubated in a germination chamber (BOD type) at a temperature of 20 ºC (± 2 ºC) during 0 h (control), 6 h, 12 h and 24 hours, under continuous light. For each species, the experiment was carried out in a completely randomized factorial with 5 (priming treatments) x 4 (priming time) factors and four repetitions of 20 seeds. The percentage of germination, germination speed index, length of root and aerial parts, and fresh and dry mass of seedlings obtained from seeds conditioned in -1.0 MPa osmotic potential and the %G and IGS of those conditioned at -0.5 MPa, were evaluated. Priming in the potential of -1.0 MPa did not significantly influence the physiological performance of Stryphnodendron obovatum and S. polyphyllum seeds but the development of S. adstringens seeds was adversely affected. Priming of S. adstringens and S. polyphyllum seeds in potential of -0.5MPa results in higher percentage germination and germination speed index.
The objective of this study was to evaluate the germination of seeds of three species of Stryphnodendron Mart. (Stryphnodendron adstringens (Mart.) Coville, S. obovatum Benth. and S. polyphyllum Mart.) under priming in different osmotic agents, in osmotic potentials of -1.0 MPa and -0.5 MPa. Seeds scarified in concentrated sulphuric acid for 40 minutes were conditioned in the following treatments: 1) PEG 6000; 2) PEG 6000 + KNO3, in equal parts; 3) KNO3; 4) Water and 5) Control. Afterwards, they were incubated in a germination chamber (BOD type) at a temperature of 20 ºC (± 2 ºC) during 0 h (control), 6 h, 12 h and 24 hours, under continuous light. For each species, the experiment was carried out in a completely randomized factorial with 5 (priming treatments) x 4 (priming time) factors and four repetitions of 20 seeds. The percentage of germination, germination speed index, length of root and aerial parts, and fresh and dry mass of seedlings obtained from seeds conditioned in -1.0 MPa osmotic potential and the %G and IGS of those conditioned at -0.5 MPa, were evaluated. Priming in the potential of -1.0 MPa did not significantly influence the physiological performance of Stryphnodendron obovatum and S. polyphyllum seeds but the development of S. adstringens seeds was adversely affected. Priming of S. adstringens and S. polyphyllum seeds in potential of -0.5MPa results in higher percentage germination and germination speed index.
Descrição
Palavras-chave
barbatimão, Cerrado, polietilenoglicol 6000, pré condicionamento, germinação, Stryphnodendron, Savanna, polyethylene glycol 6000, preconditioning, germination
Como citar
Revista Brasileira de Sementes. Associação Brasileira de Tecnologia de Sementes, v. 32, n. 2, p. 26-35, 2010.