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

Abstract

AbstractSeeds can synchronize their germination and dormancy cycles to regular seasonal environmental changes. The present work sought to evaluate thein-situlongevity of the buried seeds of two species ofSyngonanthusand two species ofComanthera(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− 2s− 1) at optimal germination temperature. The seeds ofComantherashowed high deterioration after the first year of burial, especiallyC. elegans, which reflects their incapacity to form viable soil seed banks. The buried seeds ofC. bisulcata, S. anthemidiflorusandS. verticillatusacquired 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 thatC. bisulcata, S. anthemidiflorus, andS. verticillatusform seed banks of the persistent type and demonstrate consecutive cycles of germination/dormancy, accompanying annual seasonal changes for at least 2 years.