Krch K. Embryology of tribe Potentilleae (Rosaceae)

The dissertation is devoted to the studies of male and female generative structures, features of seed reproduction in tribe Potentilleae species. Their microsporogenesis has been studied, and the pollen grains fertility has been revealed. A boundary between the sporogenic and somatic cells was determined when the forms of apomixis were being established in Potentilla argentea, which enabled to bring out the genesis of apomictic embryo sacs. The tribe includes sexual species - Dryas octopetala, Potentilla alba, Potentilla reptans, as well as sexual ones with the elements of apomixes - Parageum montanum, Fragaria vesca, and a facultative apomict - P. argentea with predominance of apospory. In the local populations of P. argentea agamo-sexual complexes were found. The features of formation of the primary endosperm nucleus and embryo development in sexual and apomictic species of tribe Potentilleae have been study.