Ontogeny and Population Structure of Xanthoria parietina(L.) Th. Fr. under Different Ecological Conditions

Abstract

With regard to the concept of a discrete approach to the description of seed plant ontogeny, proposed by T.A. Rabotnov and A.A. Uranov, the ontogeny of apothecial foliose lichen Xanthoria parietinais described. Four periods and 13 ontogenetic states are distinguished by morphological and anatomical characters. In the urban environment, the thalli of X. parietinaperish at early developmental stages (incomplete ontogeny); in general, their size and the number and size of apothecia decrease and the connection with substrates at the final ontogenetic stages becomes weaker. Adaptation of the X. parietinapopulation to existence under adverse natural and anthropogenic conditions manifests itself in the retarded development of pregenerative individuals and elimination of the least tolerant generative individuals.