Changes in the structure of the rhizosphere complex of actinomycetes in the ontogenesis of winter rye

Changes in the taxonomic structure of actinomycetes in the rhizosphere of winter rye (Secale cereale L.) growing on acid soddy-podzolic soil were studied. During the first stages of ontogenesis of winter rye, the rhizosphere complex of mycelial prokaryotes was characterized by a relatively level generic structure (with respect to the indices of abundance and frequency of particular genera), low values of the species diversity, and low domination frequency of the species from the Streptomyces genus. The numbers and species diversity of the streptomycetes increased during the further growth of the winter rye, so that streptomycetes became a dominant group in the complex of the rhizosphere actinomycetes. According to the two-way ANOVA, the population density of the Micromonospora and the Streptosporangium genera in the rhizosphere was mainly dictated by the winter rye variety, whereas the population density of the streptomycetes depended on the particular stage of the winter rye development. The differences between the actinomycetal complexes characteristic of different varieties of winter rye at the early stages of its development was leveled by the end of the winter rye growth.