Abstract:

The after-ripening physiology and roles of endogenous hormones of Ginkgo (Ginkgo biloba) seeds were studied in this paper. The results showed that seed embryo uncompleted differentiation and uncompleted development were the main reasons for Ginkgo seeds dormancy; the after-ripening was a process of embryo differentiation and growth of Ginkgo seeds. After morphological ripening, the seeds must go through a series of physiological and biochemical changes in order to finish embryo development and endogenous hormones balances. Some plant endogenous hormones such as ABA, GA and ZRs acted an important role in the every stage of seed dormancy and germination. GA₁₊₃ had a decisive role during dormancy and germination of Ginkgo seeds. ZRs could induce the growth of fruits, but was not the necessitate factor of dormancy and germination. The relative ratio of GA₁₊₃ABA and ZRsABA may play a more important role than their absolute level during the seed development and embryo after-ripening.

Key words: Ginkgo seeds, endogenous hormones, GA₁₊₃, ABA, ZRs, physiochemical changes