Natural Regeneration of Ginkgo Biloba From Downward Growing Cotyledonary Buds (Basal Chichi)

This study describes the origin and early development of a distinct organ of clonal regeneration in Ginkgo biloba, the basal chichi. These aggregates of suppressed shoot buds originate from superficial meristems located in the cotyledonary axils of all Ginkgo seedlings as part of their normal ontogeny. Within 6 wk of germination these buds become embedded in the cortex of the stem, and their subsequent growth and development occurs below the surface of the bark. When stimulated by some traumatic event that damages the seedling axis, one of these embedded cotyledonary buds usually grows down from the trunk to form a woody, rhizomelike basal chichi which, under appropriate conditions, is capable of generating both aerial shoots and adventitious roots. Vegetative regeneration by means of basal chichi has not only contributed to the long‐term persistence of G. biloba in the forests of China, but may also have played a role in the remarkable survival of the genus since the Cretaceous.