Seasonal changes in germination and dormancy of buried seeds of endemic Brazilian Eriocaulaceae

Seeds can synchronize their germination and dormancy cycles to regular seasonal environmental changes. The present work sought to evaluate the in-situ longevity of the buried seeds of two species of Syngonanthus and two species of Comanthera (Eriocaulaceae) in the region of natural occurrence (Serra do Cipó Range, south-eastern Brazil), and to relate their germination responses to seasonal climatic changes. Samples were exhumed bimonthly and germination was tested under a 12-h photoperiod (30 μmol m − 2 s − 1 ) at optimal germination temperature. The seeds of Comanthera showed high deterioration after the first year of burial, especially C. elegans , which reflects their incapacity to form viable soil seed banks. The buried seeds of C. bisulcata, S. anthemidiflorus and S. verticillatus acquired secondary dormancy during the rainy season (spring/summer, higher temperatures) which was alleviated during the subsequent dry season (autumn/winter, lower temperatures). It is concluded that C. bisulcata, S. anthemidiflorus , and S. verticillatus form seed banks of the persistent type and demonstrate consecutive cycles of germination/dormancy, accompanying annual seasonal changes for at least 2 years.