Teste de tetrazólio para avaliação do potencial fisiológico de sementes de amendoim
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Data
2012-02-27
Autores
Santos, Juliana Faria dos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O teste de tetrazólio assume posição de destaque na avaliação do potencial fisiológico de sementes, devido ao grande número de informações fornecidas. Entretanto, a eficiência desse teste está relacionada a procedimentos apropriados e, para o amendoim, a técnica aplicada não está totalmente adequada, pois cultivares distintos podem apresentar respostas diferenciadas. Esta pesquisa objetivou adequar o teste de tetrazólio para sementes de amendoim. Oito lotes de sementes de amendoim, quatro do cv. IAC Tatu ST e quatro do Runner IAC 886, foram avaliados pelos testes de germinação, vigor (envelhecimento acelerado e condutividade elétrica) e emergência de plântulas em campo. Para o teste de tetrazólio, as sementes foram submetidas ao pré-condicionamento a 25 ºC por três, seis, nove, 12 e 16 horas (embebição direta em água - copo) e por 16 e 24 horas (embebição em papel umedecido). Após determinação do melhor período, as sementes foram preparadas com tegumento, sem tegumento e com cotilédones separados, sendo imersas em solução de tetrazólio 0,05; 0,075; 0,1 e 0,2%, a 40 ºC, por duas horas. O melhor período de pré-condicionamento foi o de 16 horas (copo). A solução de tetrazólio 0,05% para o cv. IAC Tatu ST em todos os preparos permitiu maior diferenciação entre lotes e para o cv. Runner IAC 886 as concentrações 0,075% em sementes com tegumento e com cotilédones separados e 0,2% para sementes sem tegumento foram as melhores. Assim, o teste de tetrazólio para sementes de amendoim deve ser conduzido com pré-condicionamento por 16 horas diretamente em água, preparo sem tegumento com imersão em solução de tetrazólio 0,05%, para cv. IAC Tatu ST, e preparo com cotilédones separados e imersão em solução 0,075%, para cv. Runner IAC 886
The tetrazolium test stands out in the physiological assessment of the seeds, given the large number of information provided. However, the efficiency of this test is related to accurate procedures and for peanut seeds, the applied technique is not entirely appropriate, since different cultivars may have different responses. This study aimed to adjust the tetrazolium test for peanut seeds. Eight lots of peanut seeds, four of the cv. IAC Tatu ST and four of the Runner IAC 886, were evaluated by germination, vigor (accelerated aging and electrical conductivity) and seedling emergence in the field tests. For tetrazolium test, seeds were submitted to preconditioning at 25 ºC for three, six, nine, 12 and 16 hours (immersed directly in water - cup) and for 16 and 24 hours (moistened germination paper). After determining the best preconditioning period, seeds with and without seedcoat and with separated cotyledons were submitted to staining in 0.05%, 0.075%, 0.1% and 0.2% tetrazolium solutions at 40 ºC for two hours. The best preconditioning period was 16 hours (cup). For cv. IAC Tatu ST, 0.05% tetrazolium solution permitted a greater differentiation between seed lots. For cv. Runner IAC 886, staining seeds with seedcoat and with separated cotyledons in 0.075% tetrazolium solution and seeds without seedcoat in 0.2% solution promoted better results. Thus, the tetrazolium test for peanut seeds should be conducted with 16 hours of preconditioning directly in water, without seedcoat followed by staining in 0.05% tetrazolium solution for cv. IAC Tatu ST, and with separated cotyledons and staining in 0.075% tetrazolium solution for cv. Runner IAC 886
The tetrazolium test stands out in the physiological assessment of the seeds, given the large number of information provided. However, the efficiency of this test is related to accurate procedures and for peanut seeds, the applied technique is not entirely appropriate, since different cultivars may have different responses. This study aimed to adjust the tetrazolium test for peanut seeds. Eight lots of peanut seeds, four of the cv. IAC Tatu ST and four of the Runner IAC 886, were evaluated by germination, vigor (accelerated aging and electrical conductivity) and seedling emergence in the field tests. For tetrazolium test, seeds were submitted to preconditioning at 25 ºC for three, six, nine, 12 and 16 hours (immersed directly in water - cup) and for 16 and 24 hours (moistened germination paper). After determining the best preconditioning period, seeds with and without seedcoat and with separated cotyledons were submitted to staining in 0.05%, 0.075%, 0.1% and 0.2% tetrazolium solutions at 40 ºC for two hours. The best preconditioning period was 16 hours (cup). For cv. IAC Tatu ST, 0.05% tetrazolium solution permitted a greater differentiation between seed lots. For cv. Runner IAC 886, staining seeds with seedcoat and with separated cotyledons in 0.075% tetrazolium solution and seeds without seedcoat in 0.2% solution promoted better results. Thus, the tetrazolium test for peanut seeds should be conducted with 16 hours of preconditioning directly in water, without seedcoat followed by staining in 0.05% tetrazolium solution for cv. IAC Tatu ST, and with separated cotyledons and staining in 0.075% tetrazolium solution for cv. Runner IAC 886
Descrição
Palavras-chave
Amendoim - Sementes - Viabilidade, Semente - Testes
Como citar
SANTOS, Juliana Faria dos. Teste de tetrazólio para avaliação do potencial fisiológico de sementes de amendoim. 2012. x, 45 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2012.