Método alternativo para submeter sementes de amendoim à solução de tetrazólio
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Data
2009-01-01
Autores
Carvalho, Nelson Moreira de [UNESP]
Silva, Josué Bispo da
Silveira, César Martorelli da [UNESP]
Horvat, Renata Alves [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Tecnologia de Sementes (ABRATES)
Resumo
A técnica para a determinação da viabilidade de sementes de amendoim por meio do tetrazólio (TZ) é, atualmente, aquela pela qual as sementes, após embebição em água, têm o tegumento removido. A seguir as sementes são, em grupo, imersas na solução de TZ. Essa técnica dificulta o contato entre os tecidos das faces internas dos cotilédones e a solução de TZ em virtude de que o período prévio de embebição em água não é suficiente para que os cotilédones das sementes de amendoim se separem. Assim, o acesso da solução de TZ aos tecidos das faces internas dos cotilédones e ao próprio eixo embrionário, que fica entre as duas faces cotiledonares internas, é consideravelmente dificultado. Na suposição de que este procedimento levaria a resultados de testes de TZ que se correlacionam mal com o desempenho germinativo das sementes no campo, tentou-se uma nova técnica pela qual as sementes, após a embebição em água, além de terem o tegumento removido, são manualmente separadas em seus cotilédones, com o eixo embrionário ligado a um deles, e os cotilédones de uma determinada semente, agora separados, imersos na solução de TZ contida em uma célula individual de uma bandeja de PVC. A hipótese aqui formulada mostrou-se correta : a técnica alternativa de submissão das sementes de amendoim à solução de tetrazólio permitiu a obtenção de resultados que, comparados com os da técnica convencional, refletiram de modo mais preciso o desempenho germinativo das sementes no campo.
To determine the viability of peanut seeds by means of the tetrazolium (TZ) test, the methodology in use nowadays is that by which the seeds, after imbibition in water, have their tegument removed and are then immersed in bulk in the TZ solution. This technique hinders the contact between the tissues of the internal surfaces of the seed cotyledons and the TZ solution because the previous period of water imbibition is not long enough to separate the cotyledons. Thus, the access of the TZ solution to the inner surfaces of the cotyledons and to the embryonic axis between them is very difficult or even impossible. Based on the assumption that this procedure tends to yield results which do not correlate well with seedling emergence in the field, a new technique was attempted by which the seeds, after imbibition, in addition to having their tegument removed, were manually separated in their cotyledons, with the embryonic axis remaining attached to one of them, and the two cotyledons of the same seed were then immersed in the TZ solution in an individual cell of a PVC tray. The assumption was found to be correct : the alternative technique, probably because it resulted in more clearly defined images of the tissues located inside the cotyledons internal surfaces, allowed, in comparison with the results of the conventional technique, more precise predictions of the seeds germination performance in the field.
To determine the viability of peanut seeds by means of the tetrazolium (TZ) test, the methodology in use nowadays is that by which the seeds, after imbibition in water, have their tegument removed and are then immersed in bulk in the TZ solution. This technique hinders the contact between the tissues of the internal surfaces of the seed cotyledons and the TZ solution because the previous period of water imbibition is not long enough to separate the cotyledons. Thus, the access of the TZ solution to the inner surfaces of the cotyledons and to the embryonic axis between them is very difficult or even impossible. Based on the assumption that this procedure tends to yield results which do not correlate well with seedling emergence in the field, a new technique was attempted by which the seeds, after imbibition, in addition to having their tegument removed, were manually separated in their cotyledons, with the embryonic axis remaining attached to one of them, and the two cotyledons of the same seed were then immersed in the TZ solution in an individual cell of a PVC tray. The assumption was found to be correct : the alternative technique, probably because it resulted in more clearly defined images of the tissues located inside the cotyledons internal surfaces, allowed, in comparison with the results of the conventional technique, more precise predictions of the seeds germination performance in the field.
Descrição
Palavras-chave
Arachis hypogaea, seed viability determination, seedling emergence, Arachis hypogaea, determinação da viabilidade de sementes, Emergência de plântulas
Como citar
Revista Brasileira de Sementes. Associação Brasileira de Tecnologia de Sementes, v. 31, n. 1, p. 18-22, 2009.