BIOMORPHOLOGICAL FEATURES OF HELLEBORUS PURPURASCENS WALDST. & KIT.

Abstract

Helleborus purpurascens Waldst. & Kit. – a valuable medicinal and decorative plant. Biomorphological research as a component of a comprehensive study of the species is the basis for the development of a set of measures for the preservation of natural populations and for the further wide application of economic and valuable traits of plants in their cultivation. The ontomorphogenesis of H. purpurascens under culture conditions in the Sofiyivka National Dendrological Park of the National Academy of Sciences of Ukraine was investigated. It was found that at all stages of the virginal period of ontogenesis monopodial growth of the axial shoot takes place with the dominance of the apical meristem. Traumatic elimination of the apical meristem at all stages of the virginal period leads to the replacement of the axial shoot by a lateral one, but does not promote branching. In the typical course of ontogenesis, the generative period begins in the fourth year of life of individuals, after which there is a transition to the sympodial model of shoot formation. Monocarpic shoots develop according to the type of dicyclic, development according to the type of incomplete, oligo- or polycyclic are manifestations of polyvariance. Features of the structural and functional organization of monocarpic shoots are described, their morpho-structural zones are characterized. It was found that: the lower inhibition zone (LIZ) is represented by 2-3 metamers with short internodes and cataphylls with dormant buds in their axils; innovation zone (IZ) – one (2) metamer(s) with a short internode and a cataphyll with a renewal bud in its axil; middle inhibition zone (MIZ) – one (2-3) metamer with a photophilic typical leaf(s) of the middle formation; amplification zone (AZ) – inflorescences of the cymoid type. According to the nature of the location of individual structural elements of the shoot and root sphere within the adult individual, H. рurpurascens belongs to monocentric, vegetatively immobile biomorphs, the destruction of the axial part of the main shoot in which does not lead to natural vegetative reproduction and an increase in the number of individuals.