Avaliação do potencial fisiológico de sementes de mutamba (Guazuma ulmifolia Lam.) por meio de diferentes testes de vigor
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Data
2003-02-17
Autores
Gonçalves, Edilma Pereira [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O trabalho teve como objetivo verificar a eficiência de diferentes testes de vigor para identificação do potencial fisiológico de quatro lotes de sementes de mutamba (Guazuma ulmifolia Lam.). O estudo foi desenvolvido no Laboratório de Análise de Sementes e no Viveiro Experimental de Plantas Ornamentais e Florestais - UNESP, Jaboticabal, SP. Foram utilizados quatro lotes de sementes provenientes de três localidades paulistas: lotes I e 11, coletados no município de Jaboticabal em 2000 e 2001, respectivamente, lote 111, coletado em Santa Rita do Passo Quatro, e lote IV, coletado em Luiz Antonio, os dois últimos em 2001. As sementes utilizadas em todos os testes foram escarificadas com ácido sulfúrico durante 50 minutos e lavadas em água corrente durante 15 minutos. Foram avaliados: teor de água, teste de germinação, teste de primeira contagem, índice de velocidade de germinação, emergência em viveiro, índice de velocidade de emergência, envelhecimento acelerado conduzido nas temperaturas de 410e e 450e, durante nove períodos de avaliação, e condutividade elétrica com diferentes números de sementes (50, 75, 100), postas para embeber em copos de plástico contendo 50, 75 e 100 mL de água desionizada, à temperatura de 250e, fazendo leituras freqüentes durante 72 horas. Os teores de água das sementes nos diferentes lotes apresentaram pequenas variações (9,2 a 10,0 %). Não foram verificadas diferenças estatísticas para a porcentagem de germinação, emergência em viveiro e índice de velocidade de emergência. Diante dos resultados obtidos, concluiu-se que o envelhecimento acelerado pode ser realizado na temperatura de 41°C por um período mínimo de 120 horas ou a 45°C durante 96 horas para avaliação do potencial fisiológico, e o teste de condutividade elétrica não se mostrou adequado para avaliação do potencial fisiológico das sementes...
The work had as objective to compare the efficiency of different vigor tests for identification of the physiologic potential in four lots of Guazuma ulmífolia seeds. The experiments were carried out at Jaboticabal, State of São Paulo, Brazil. Four seed lots from three places of São Paulo State were used: lots I and 11, collected in the municipal district of Jaboticabal in 2000 and 2001, lot 111, collected in Santa Rita do Passa Quatro, and lot IV, collected in Luiz Antonio, the last two in 2001. The seeds used in ali the tests were escarified with sulfuric acid during 50 minutes, and washed in running water during 15 minutes. The results were evaluated with base on seed moisture content, germination test, first count test, germination speed index, emergency in nursery, emergency speed index, accelerated aging at the temperatures of 41°C and 45°C (nine evaluation periods of time) and electric conductivity with different numbers of seeds (50,75, 100), put to soak in plastic boxes containing 50, 75 and 100 mL of water, at 25°C, with frequent observations during 72 hours. The seed moisture content in the different lots presented small variations (9,2 to 10,0%). Statistical differences were not verified for the germination percentage, emergency in nursery and emergency speed index. It was concluded that the accelerated aging at 41°C during a minimum period of 120 hours or at 45°C during 96 hours can be used for evaluation of the physiologic potential of the seeds, and the test of electric conductivity was not appropriate for this purpose. The test of first count and index of germination speed showed to be adequate for evaluation of the physiologic potential of the lots. The germination tests, emergency in nursery and index of emergency speed did not detect differences in the physiologic potential of the studied lots. The seeds lot from Santa Rita do Passa Quatro presented physiologic potential superior to the other lots.
The work had as objective to compare the efficiency of different vigor tests for identification of the physiologic potential in four lots of Guazuma ulmífolia seeds. The experiments were carried out at Jaboticabal, State of São Paulo, Brazil. Four seed lots from three places of São Paulo State were used: lots I and 11, collected in the municipal district of Jaboticabal in 2000 and 2001, lot 111, collected in Santa Rita do Passa Quatro, and lot IV, collected in Luiz Antonio, the last two in 2001. The seeds used in ali the tests were escarified with sulfuric acid during 50 minutes, and washed in running water during 15 minutes. The results were evaluated with base on seed moisture content, germination test, first count test, germination speed index, emergency in nursery, emergency speed index, accelerated aging at the temperatures of 41°C and 45°C (nine evaluation periods of time) and electric conductivity with different numbers of seeds (50,75, 100), put to soak in plastic boxes containing 50, 75 and 100 mL of water, at 25°C, with frequent observations during 72 hours. The seed moisture content in the different lots presented small variations (9,2 to 10,0%). Statistical differences were not verified for the germination percentage, emergency in nursery and emergency speed index. It was concluded that the accelerated aging at 41°C during a minimum period of 120 hours or at 45°C during 96 hours can be used for evaluation of the physiologic potential of the seeds, and the test of electric conductivity was not appropriate for this purpose. The test of first count and index of germination speed showed to be adequate for evaluation of the physiologic potential of the lots. The germination tests, emergency in nursery and index of emergency speed did not detect differences in the physiologic potential of the studied lots. The seeds lot from Santa Rita do Passa Quatro presented physiologic potential superior to the other lots.
Descrição
Palavras-chave
Plantas florestais - Semente, Guazuma ulmifolia, Heterose, Forest plants - seeds
Como citar
GONÇALVES, Edilma Pereira. Avaliação do potencial fisiológico de sementes de mutamba (Guazuma ulmifolia Lam.) por meio de diferentes testes de vigor. 2003. xv, 64 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, 2003.