Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 3

A structural and rhythmological analysis of shoot systems of three Atraphaxis species was carried out. The species demonstrate differences in the structure of terminal synflorescences, floral units, and generative shoots. The duration of spring-summer blossoming of Atraphaxis is determined by the number and branching order of paracladia in synflorescence and the length of generative shoots. The species differ in the morphological differentiation of the axes and in the distribution of functions between generative and vegetative shoots. In A. frutescens , the main skeletal axes are built on the basis of generative shoots, which perform both the assimilative and reproductive functions. This species takes the life form of aeroxylic shrub, dwarf shrub or semi-shrub, depending on the preserved part of vegetative zone of generative shoots, which is determined by wintering conditions. In A. replicata , the main skeletal axes are formed on the basis of both generative and vegetative shoots. Terminal abbreviation, that is, underdevelopment of terminal synflorescence in powerful generative shoots, creates conditions for the transfer of reproductive function to small early blooming generative shoots, which allows the species to adapt to semiarid climate. In A. pyrifolia , the formation of a perennial axial system on the basis of powerful branched vegetative shoots makes it possible to more fully realize the advantages of acrotonic branching and to achieve a significant size. The specialization of generative shoots in the performance of the reproductive function is realized most fully in this species.