Action of gibberellic acid (GA3) on dormancy and activity of alpha-amylase in rice seeds

• Autor(a) principal: Vieira,Antônio Rodrigues
• Data de Publicação: 2002
• Outros Autores: Vieira,Maria das Graças Guimarães Carvalho, Fraga,Antônio C., Oliveira,João Almir, Santos,Custódio D. dos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Sementes (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0101-31222002000200008
• topic: Rice seeds; dormancy; germination; gibberellic acid (GA3); alpha-amylase

To evaluate the effectiveness of gibberellic acid (GA3) in breaking rice seed dormancy and the use of alpha-amylase enzyme activity as an indicator of the dormancy level, seed from the intensively dormant irrigated cultivar Urucuia were used. The seeds were submitted to a pre-drying process in a forced air circulation chamber under 40ºC during 7 days and submersed in 30 mL of GA3 solution under 0, 10, 30 and 60 mg/L H2O concentrations, during 2, 24 and 36 hours. After the treatments, the alpha-amylase activity was determined by using the polyacrilamide electrophoresis and spectrophotometry. At the same time, the germination test was made. The results indicated a gain in germination and in alpha-amylase activity in higher concentrations and soaking time of seeds in GA3. These observations support the conclusion that soaking seed in 60 mg GA3/L during 36 hours can be used as a quick and efficient treatment in breaking rice seed dormancy and is equivalent to the forced air circulation chamber at 40ºC during 7 days. The alpha-amylase enzyme activity proved to be as an efficient marker of the seeds dormancy level.