Fases da germinação de sementes de Annona emarginata (Schltdl.) H. Rainer em diferentes temperaturas
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Data
2011-03-01
Autores
Costa, Paula Nepomuceno [UNESP]
Bueno, Silvana Sales Catarina
Ferreira, Gisela [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Fruticultura
Resumo
O presente trabalho foi realizado com o objetivo de identificar as fases da germinação de sementes de araticum-de-terra-fria (Annona emarginata (Schltdl.) H. Rainer) sob diferentes temperaturas. Para tanto, o trabalho foi dividido em dois experimentos: um para a determinação das fases I e II da germinação, e outro para a fase III. O delineamento experimental foi o inteiramente casualizado, com 3 tratamentos e 4 repetições de 25 sementes por parcela, em ambos os experimentos. Os tratamentos foram constituídos pelas temperaturas constantes de 25ºC e 30ºC e temperatura alternada de 20-30ºC (8-16 h, respectivamente), com luz constante. As variáveis analisadas foram a variação do grau de umidade ao longo do tempo (experimento 1), a porcentagem e a velocidade média de germinação (experimento 2). Os dados foram submetidos à análise de variância, as médias comparadas pelo teste Tukey, a 5% de probabilidade e regressão polinomial. A variação do grau de umidade ao longo do tempo foi estudada através da regressão não linear monomolecular, com os parâmetros das funções comparados conforme os tratamentos, ajustados, submetidos à análise de variância e teste Tukey, a 5% de probabilidade. Observou-se que as sementes mantidas a 30ºC apresentaram maiores valores para velocidade de aquisição de água, atingindo 27,85% de grau de umidade na mudança da fase I para a fase II. Quando as sementes foram submetidas a 25ºC, a fase I teve duração de 60 horas, atingindo 28,35% de grau de umidade e, sob 20/30ºC, a fase durou 72 horas, alcançando 28,33% de grau de umidade. Embora 30ºC tenha promovido a maior velocidade de embebição, não refletiu em maior porcentagem de germinação (fase III), que foi observada nas sementes mantidas a 20/30ºC.
This study was carried out with the aimed to identify the germination phases of araticum-de-terra-fria (Annona emarginata (Schltdl.) H. Rainer) seeds under different temperatures. Thus, the work was divided into two experiments: one for evaluating phases I and II, and a second one for phase III. The experimental design was completely randomized, with 3 treatments and 4 replicates of 25 seeds per plot in both experiments. Treatments consisted of constant temperatures equal to 25ºC and 30ºC, besides the alternate temperature 20-30ºC (8-16h, respectively), under constant light. Humidity degree variation over time (experiment 1), and germination percentage and mean velocity (experiment 2) were assessed. Data were subjected to analysis of variance, and means were compared by the Tukey's test at 5% significance, besides polynomial regression. Humidity degree variation over time was evaluated through non-linear monomolecular regression; the parameters of functions were compared according to treatments, then fit and subjected to analysis of variance and Tukey's test at 5% significance. Seeds kept at 30ºC had higher water absorption velocity, peaking 27.85% humidity degree during the change from phase I to phase II. When seeds were subjected to 25ºC, phase I lasted 60 h, peaking 28.35% humidity degree. Under 20/30ºC, such phase lasted 72 h, peaking 28.33% humidity degree. The temperature 30ºC led to the highest imbibition velocity but not to a higher germination percentage (phase III), which was detected in seeds kept at 20/30ºC.
This study was carried out with the aimed to identify the germination phases of araticum-de-terra-fria (Annona emarginata (Schltdl.) H. Rainer) seeds under different temperatures. Thus, the work was divided into two experiments: one for evaluating phases I and II, and a second one for phase III. The experimental design was completely randomized, with 3 treatments and 4 replicates of 25 seeds per plot in both experiments. Treatments consisted of constant temperatures equal to 25ºC and 30ºC, besides the alternate temperature 20-30ºC (8-16h, respectively), under constant light. Humidity degree variation over time (experiment 1), and germination percentage and mean velocity (experiment 2) were assessed. Data were subjected to analysis of variance, and means were compared by the Tukey's test at 5% significance, besides polynomial regression. Humidity degree variation over time was evaluated through non-linear monomolecular regression; the parameters of functions were compared according to treatments, then fit and subjected to analysis of variance and Tukey's test at 5% significance. Seeds kept at 30ºC had higher water absorption velocity, peaking 27.85% humidity degree during the change from phase I to phase II. When seeds were subjected to 25ºC, phase I lasted 60 h, peaking 28.35% humidity degree. Under 20/30ºC, such phase lasted 72 h, peaking 28.33% humidity degree. The temperature 30ºC led to the highest imbibition velocity but not to a higher germination percentage (phase III), which was detected in seeds kept at 20/30ºC.
Descrição
Palavras-chave
Annonaceae, araticum-de-terra-fria, embebição, Annonaceae, araticum-de-terra-fria, imbibition
Como citar
Revista Brasileira de Fruticultura. Sociedade Brasileira de Fruticultura, v. 33, n. 1, p. 253-260, 2011.