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Information × Registration Number 0211U002886, 0107U000082 , R & D reports Title Investigation of the sexual reproduction, breedig systems and life cycles of diatoms. popup.stage_title Head DAVIDOVICH Nickolai Aleksandrovich, Registration Date 09-03-2011 Organization Karadag Natural Preserve National Academy of Sciences of the Ukraine popup.description2 Research reports: 41., 1 appendix (p. 42-75), 54 sources. The object of study - raphid and araphid pennate diatoms. The purpose of the work - study of life cycles and reproduction systems of diatoms. Methods of research - clonal cultivation, crossing, observation. The sexual reproduction, mating systems and life cycles of raphid and araphid diatoms were studied. Methodologically this work was based on clonal cultures of algae, isolated from planktonic, benthic and periphytonic samples from natural populations. We have found sexual reproduction in some marine species, Haslea ostrearia (heterothally), Haslea sf. ostrearia, Tabularia tabulata, T. fasciculata, and freshwater Synedra ulna. Cytological description of the process of sexual reproduction has been provided for these species. It was shown that all species can combine in their breeding system two ways - homothallic and heterothallic, the latter being dominant (basic), while homothallic way registered optionally. Under laboratory conditions, we have obtained data on cell size changes in the life cycle of the algae that allowed us to relate the size characteristics of algae with passage through the life-cycle phases in natural populations. On the basis of crossing experiments we have confirmed the existence in the Black Sea of a species Haslea cf. ostrearia, which is similar to the already well-known form Haslea ostrearia, but reproductively isolated from it. Hence, by using techniques of reproductive biology we have revealed a new species. To obtain additional evidence the work has been done on the properties of a pigment marennin typical for these species. molecular and genetic differences were also studied. In T. fasciculata we revealed a new, previously unknown type of gamete movement. By studying the sex of offspring, which was formed as a result of heterothallic and homothallic reproduction we proved diplogenotypic model of sex determination and inheritance in diatoms. Product Description popup.authors Давідович O.I. Подунай Ю. А. Шоренко К. І. popup.nrat_date 2020-04-02 Close