The effect of temperature on the germination and endogenous cytokinin and gibberellin levels of pecan nuts

Abstract

Summary Incubation of pecan embryos at 30 °C resulted in an increase in the level of endogenous cytokinins and gibberellins and also gave optimum germination. A much slower rate of hormone production occurred with incubation at 20 °C and this is possibly correlated with the poor germination obtained at this temperature. Incubation at 4 °C partly substituted for the high temperature germination requirement and resulted in hormonal changes very similar to those recorded at 30 °C. Kinetin and gibberellin acid were also found to substitute partially for the high temperature requirement. These results suggest that endogenous hormones may play an important role in the mobilization of lipid food reserves to supply the energy required for germination.