Is the loss of desiccation tolerance in orthodox seeds affected by provenance?

Abstract

There is little information about the influence of the environment on seed morphological and physiological characteristics, especially on desiccation tolerance. Therefore, the objective of this study was to investigate the loss of desiccation tolerance in germinating orthodox seeds of the tree species Copaifera langsdorffii from different provenances. Seeds were harvested from the Cerrado stricto sensu in Montes Claros and Lavras, and the riparian forest in Lavras. These cities are located, respectively, in the north and south of the State of Minas Gerais, Brazil. The climate in the north of the State shows higher temperatures and lower precipitation than the south. For each provenance, a seed imbibition curve was constructed by measuring the increase in seed water content with incubation time. Seeds were then imbibed for different periods of time, dried and subsequently rehydrated in order to assess survival (desiccation tolerance). Additionally, the effect of pre-imbibition over water and scarification on desiccation tolerance was assessed for seeds from Montes Claros. It was observed that seeds from the Cerrado of Montes Claros are more desiccation-tolerant than those from Lavras, highlighting that the maternal environment influences desiccation tolerance. Pre-imbibition and scarification did not influence desiccation tolerance.