Anatomical investigations determining the origin of crown buds on the transition zone of gentians

Abstract

Gentians are herbaceous perennials of ornamental and medicinal value, which utilize preformed crown buds as part of the perennating structure. Understanding the morphology and associated development of these crown buds is required if manipulation of bud initiation, emergence and development are to be achieved. The point of origin of crown buds, or whether crown buds originate from axillary or adventitious meristems, has not previously been published. In the current study, therefore, anatomical features of the shoot/stem, storage root, transition zone between shoot and root, axillary buds and crown bud clusters, were examined using light microscopy. In seedlings of Gentiana lutea, G. straminea, G. triflora and G. scabra, the transition zone was determined to be the area of initiation of crown buds, which differed morphologically in vascular arrangement from both the true shoot/stem and storage root. Crown buds that first developed on the transition zone were considered to be adventitious in origin.