ABSTRACTWe studied the effects of seed storage on germination and dormancy alleviation in three species of Fabaceae endemic to campo rupestrein southeastern Brazil. Fresh seeds of Collaea cipoensis, Mimosa maguirei and Mimosa foliolosawere set to germinate and germination of seeds after four, five and 13 years of storage was tested. Seed viability was maintained for all species after the full storage period. Seed storage significantly increased germination percentage and decreased germination time for C. cipoensisand M. foliolosa, suggesting the alleviation of physical dormancy with storage. However, we did not find evidence of dormancy alleviation in M. maguirei since stored seeds showed a decrease in germination in comparison to that of fresh seeds. Our data indicate species-specific storage-mediated dormancy alleviation, which will have important implications for restoration of campo rupestre.

Seed dormancy is a widely misunderstood plant trait. In several research areas, a lack of germination is wrongly assumed to result from seed dormancy. In an attempt to standardize seed dormancy research and improve communication among seed scientists, a straightforward protocol to address the occurrence and causes of seed dormancy is provided. Standardizing communication is not just a theoretical exercise but also has practical implications in agriculture and conservation. Standardization will make studies comparable and hence we will have a deeper understanding of the physiology, ecology and evolution of seed dormancy. A better understanding of the various aspects of seed dormancy will lead to greater appreciation of the biogeographical and phylogenetic distribution of seed dormancy among our flora.

Neste estudo foram investigados os efeitos da luz, temperatura e armazenamento na germinação de sementes do ananás, Ananasananassoides, uma bromélia de sub-bosque de cerradão. As sementes foram submetidas aos testes nas temperaturas de 15, 20, 25, 30 e 35 ºC em fotoperíodo de 12 horas e escuro contínuo por 30 dias. As sementes foram consideradas fotoblásticas e as temperaturas ótimas para germinação foram 25 e 30 ºC. Sementes armazenadas por 12 meses a temperatura ambiente e a 4 ºC foram colocadas para germinar nas condições ótimas e apresentaram germinabilidade e tempo médio de germinação similares à sementes recém-coletadas independente da temperatura de armazenamento, demonstrando potencial fisiológico para formação de banco de sementes. Os resultados sugerem que de forma similar às florestas tropicais, a luz pode ser um importante fator que controla o recrutamento de plântulas a partir do banco de sementes para espécies de sementes pequenas de cerradão.

In this study we investigated the effects of light, temperature, and storage on seed germination of the wild pineapple Ananasananassoides, an understorey species found in cerrado woodlands. Seeds were germinated at temperatures of 15, 20, 25, 30 and 35 ºC and a 12-hr photoperiod and continuous darkness for 30-d. Seeds were photoblastic and the optimum temperatures for germination were 25 and 30 ºC. Seeds stored for 12-mo at room temperature and at 4 ºC were set to germinate at optimum conditions. Germinability of stored seeds did not differ from that of recently collected seeds, regardless of storage temperature, indicating their physiological potential for seed bank formation. Our results suggest that as in tropical rainforests, light may be an important factor controlling recruitment from seed banks for small-sized species from the cerrado woodlands.