Testes de vigor em sementes de Guazuma ulmifolia Lam.
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Data
2008-04-01
Autores
Gonçalves, Edilma Pereira
Paula, Rinaldo César de [UNESP]
Desmattê, Maria Esmeralda Soares Payão [UNESP]
Título da Revista
ISSN da Revista
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Editor
Universidade Estadual de Londrina (UEL)
Resumo
O trabalho teve como objetivo estudar a eficiência dos testes de vigor para identificação do potencial fisiológico em sementes de Guazuma ulmifolia Lam. O estudo foi desenvolvido no Laboratório de Análise de Sementes – UNESP/Jaboticabal/SP, utilizando-se quatro lotes de sementes: sendo lotes I e II, coletados no município de Jaboticabal em 2000 e 2001, respectivamente lote III em Santa Rita do Passo Quatro e lote IV, em Luiz Antonio, ambos em 2001. Para superação da dormência, realizou-se a escarificação das sementes com ácido sulfúrico durante 50 minutos e lavagem em água corrente durante 20 minutos. Foram avaliados: teor de água, percentual de germinação, primeira contagem, índice de velocidade de germinação e condutividade elétrica, realizada com diferentes quantidades de sementes (50, 75, 100), postas para embeber em copos de plástico contendo 50 e 75mL de água deionizada, durante 72 horas à 250 C. As sementes do lote III apresentaram potencial fisiológico superior às sementes dos demais lotes estudados. Para o teste de condutividade elétrica são necessários outros estudos, visando à possibilidade de uso como teste padrão de vigor para a espécie, enquanto que os testes de primeira contagem e índice de velocidade de germinação mostraram-se adequados para avaliação do vigor dos lotes.
The work had as objective to verify the efficiency of vigour tests for identification of the physiologic potential in four lots of seeds of Guazuma ulmifolia Lam. The study was developed at the Laboratory of Seed Analysis - UNESP, Jaboticabal, SP. Four lots of seeds from three places of São Paulo state were used: lots I and II, collected in the municipal district of Jaboticabal in 2000 and 2001; lot II,: collected in Santa Rita do Passa Quatro and lot IV, Luiz Antonio, both in 2001. To break seed dormancy the seeds used in all the tests were escarified with sulfuric acid during 50 minutes, and washed in running water during 20 minutes. The evoluations were: seed moisture content, germination percentage, first count test, germination speed index and electric conductivity with different numbers of seeds (50, 75, 100) put to soak in plastic containing 50 and 75mL of water, to the temperature at 25 degrees C, during for 72 hours. The seeds of the lot originating from lot III, presented physiologic potential superior to the other studied lots. The tests of electric conductivity, first count, and index of germination speed were appropriate for evaluation of the physiologic potential of the lots. For the electric conductivity test other studies are necessary, involving a larger number of lots, seeking the use possibility a pattern vigour test, while the tests of first count and index of germination speed were appropriate for evaluation of the vigour.
The work had as objective to verify the efficiency of vigour tests for identification of the physiologic potential in four lots of seeds of Guazuma ulmifolia Lam. The study was developed at the Laboratory of Seed Analysis - UNESP, Jaboticabal, SP. Four lots of seeds from three places of São Paulo state were used: lots I and II, collected in the municipal district of Jaboticabal in 2000 and 2001; lot II,: collected in Santa Rita do Passa Quatro and lot IV, Luiz Antonio, both in 2001. To break seed dormancy the seeds used in all the tests were escarified with sulfuric acid during 50 minutes, and washed in running water during 20 minutes. The evoluations were: seed moisture content, germination percentage, first count test, germination speed index and electric conductivity with different numbers of seeds (50, 75, 100) put to soak in plastic containing 50 and 75mL of water, to the temperature at 25 degrees C, during for 72 hours. The seeds of the lot originating from lot III, presented physiologic potential superior to the other studied lots. The tests of electric conductivity, first count, and index of germination speed were appropriate for evaluation of the physiologic potential of the lots. For the electric conductivity test other studies are necessary, involving a larger number of lots, seeking the use possibility a pattern vigour test, while the tests of first count and index of germination speed were appropriate for evaluation of the vigour.
Descrição
Palavras-chave
Potencial fisiológico, Condutividade elétrica, Sementes florestais, Physiologic potential, Electric conductivity, Forest seeds
Como citar
Semina: Ciências Agrárias. Londrina: Universidade Estadual de Londrina (UEL), v. 29, n. 2, p. 265-276, 2008.