The packaging, used to maintain the seeds during storage, is extremely important in their conservation. Seeds from the cultivar BAT 2101 were used in order to evaluate the effect of packaging on the conservation of the quality of bare and pelleted tobacco seeds stored in the long-term. After characterization of the lot profile, the seeds were stored for 180, 360, 540, and 720 days under ambient conditions at 25 °C ± 2 and 62.8% relative humidity in cotton bags, aluminum cans, laminated envelopes, plastic envelopes and paper envelopes. The seed quality throughout the storage in the different packages was determined by the water content and germination tests, first germination count, germination speed index, initial and final emergence and emergence speed index. The aluminum can packaging keeps the quality of bare and pelleted tobacco seeds for a period of 720 days. Up to 360 days of storage, there was a decrease in the dormancy of bare and pelleted seeds with an increase in deterioration after this period, except for those kept in the aluminum can packing.

ABSTRACT. Evaluation of the physiological potential of maize seeds during the certification process is performed by a germination test. However, some tests show a delay in the growth of aerial seedling organs that does not reflect seed lot behavior in the field. This study aims to investigate the effects of genotype, water, light and temperature on differential primary leaf growth compared to coleoptile length in maize seedlings. Seeds from two simple hybrids and their reciprocal crosses that showed slow primary leaf growth were evaluated according to physiological quality, morphology, histochemistry, and enzymatic expression. There were differences among maize genotypes regarding initial primary leaf growth when compared to the coleoptile, especially when germination was tested without light. Water availability and optimal temperature range did not affect the differential growth of the primary leaf in the hybrids. Pericarp thickness, lignin content and differences in enzyme expression in different genotypes were also not related to changes in the relationship of primary leaf growth with coleoptile length during the maize seed germination test.Keywords: Zea mays L.; germination test; lignin; enzymes.Crescimento diferencial da plúmula e do comprimento do coleóptilo de plântulas de milho RESUMO. A avaliação do potencial fisiológico de lotes de sementes de milho no processo de certificação é realizada pelo teste de germinação. No entanto, em alguns testes, são observados atrasos no crescimento das estruturas da parte aérea das plântulas, o que leva a considerá-las plântulas anormais, mas não reflete o comportamento do lote no campo. Objetivou-se, neste trabalho, investigar o efeito do genótipo, água, luz e temperatura sobre o crescimento diferencial da plúmula em relação ao comprimento do coleóptilo de plântulas de milho. Sementes de dois híbridos simples e dos seus recíprocos com característica de crescimento lento da plúmula, foram avaliadas em sua qualidade fisiológica, morfológica, histoquímica e expressão enzimática. Existem diferenças entre genótipos de milho no que se refere ao crescimento inicial da plúmula em relação ao coleóptilo, principalmente na ausência de luz no teste de germinação. Disponibilidade hídrica e temperatura não afetam a resposta dos híbridos em relação ao crescimento diferencial da plúmula. Espessura do pericarpo, presença de lignina ou diferenças na expressão das enzimas dos genótipos não estão relacionadas às variações de comprimento plúmula/coleóptilo, durante o teste de germinação.Palavras-chave: Zea mays L.; teste de germinação; lignina; enzimas.