Thermal dependence in seed germination of Diospyros inconstans Jacq. (Ebenaceae)

Defining the cardinal temperatures for germination in the scenario of climate change with prediction of an increased terrestrial temperature plays an important role in conserving plant resources. This study aimed to define the cardinal temperatures, the time of conducting germination tests, and to apply the thermal time model for seeds of Diospyros inconstans. Thermal screening was carried out, based on germination tests performed in BOD chambers, at constant temperatures of 10, 20, 25, 30 and 40 °C, under a photoperiod of 12 hours/light. The cardinal temperatures for germination of D. inconstans seeds are 26.7 °C (optimal temperature), 13.8 °C (minimum temperature) and 37.7 °C (maximum temperature). Germination tests for the species can be conducted at optimum temperature, lasting 26 days for radicle emission and 63 days for formation of normal seedlings.