Role of the Seed Coat in Dormancy of Eucalyptuspauoiflora and E. Delegatensis Seeds

Abstract

Gibberellic acid promotes the germination of dormant seeds of some eucalypt species including Eucalyptus pauciflora Sieb. and E. delegatensis R. T. Baker. It was suggested that gibberellic acid may stimulate germination by promoting enzymatic weakening of the seed coat (Bachelard 1967) as described for Phacelia tanacetifolia seeds (Chen and Thimann 1964). Previously, Grose (1963) suggested dormancy of of E. delegatensis seeds might be due to the seed coat limiting gaseous exchange.