Viabilidade de sementes de Citrus limonia Osb. com baixo teor de umidade, armazenadas em diferentes temperaturas

“Limão-cravo" seeds with initial 25% moisture content were dried up to 6% moisture content, kept in sealed cans and stored at 4, 18 and 25°C. Non-treated seeds (fresh seeds) were stored in paper bags at 25°C. Seed germination and moisture content were determined every two months throughout the year. A germination test was also carried out on dried seeds when they had been stored for 32 months. Fresh seeds reached around 6% moisture content after two-month storage and had their germination percentages drastically reduced throughout the storage period, reaching zero after eight-month storage. Dried seeds had a slight but significant initial drop in germinability as compared with fresh seeds. The germination percentages of dried seeds was high throughout the twelve-month period, regardless of the storage temperature. After 32-month storage the germination percentage was high only on the seeds stored at 4°C. The data suggest that seed viability of Citrus limonia Osb. can be maintained through artificial drying up to 6% moisture content and storage in sealed cans at 4°C.Sementes de limão-cravo, com teor de umidade inicial de 25%, foram secadas até 6% de umidade, enlatadas hermeticamente e armazenadas a 4, 18 e 25°C. Sementes não-tratadas (sementes frescas) foram armazenadas em sacos de papel à temperatura de 25°C. A cada dois meses durante doze meses foram determinados o teor de umidade e a germinação das sementes destes vários tratamentos. A germinação também foi verificada em sementes secas, armazenadas por 32 meses. As sementes frescas (não-tratadas) atingiram um teor de umidade ao redor de 6% após dois meses de armazenamento. A percentagem de germinação das mesmas caiu drasticamente até os seis meses de armazenamento. Após oito meses, não ocorreu mais a germinação. As sementes secas tiveram uma queda inicial pequena, porém significativa na germinação, se comparada com os resultados obtidos com sementes frescas; mas a sua percentagem de germinação se manteve sempre alta durante doze meses. Após 32 meses, a percentagem de germinação foi alta apenas quando a temperatura de armazenamento havia sido a de 4°C. Para manter a viabilidade de sementes de limão-cravo, aconselha-se a secagem artificial até cerca de 6% de umidade, enlatamento hermético e armazenamento na temperatura de 4°C

Techonolgy of Qualea grandiflora Mart. (Vochysiaceae) seeds

Qualea grandiflora Mart. (Vochysiaceae), commonly known as "pau-terra", is an arborous species native to the Brazilian savannah which possess commercial interests, as it can be used either as an ornamental or as a medicinal plant. "Pau-terra" can also be used in the heterogeneous reforestation of areas which are destined for restoration of permanent preservation degraded areas. Propagation studies with this species are scarce, being necessary then further clarification regarding the factors that influences the germination process. In this context, the objective of this work was to evaluate the influence of different temperatures, substrates and light conditions on seed germination. We selected light brown seeds which were subjected to different interactions between temperatures (15-25, 20-30, 25 and 30°C), substrate (paper, sand and vermiculite) and light (light and dark). All seeds were later dry-incubated at 32°C for 3, 6 and 12 hours. After treatments, seeds were kept in BOD at 58% RH and the following parameters were calculated: germination (%G) and germination speed index (GSI); the formation of normal and abnormal seedlings and the number dead seeds. Interaction was observed for all variables. In the optimum temperature range, the seeds behaved as photoblastic neutral or indifferent. Under alternating temperatures, darkness enhanced the germination, especially when combined with the lower temperatures. We noted that the sowing in sand, at 25°C, allowed the maintenance of suitable combinations of germination and seedling development. With respect to desiccation tolerance, "pau-terra" seeds presented an orthodox behavior, with a linear increase of the vigor as function of drying