Особенности формирования популяционно-генетической структуры кеты Oncorhynchus keta на ранних стадиях онтогенеза

• Main Author: Бачевская, Л.
• Format: Text
• Language: unknown
• Published: Федеральное государственное унитарное предприятие «Тихоокеанский научно-исследовательский рыбохозяйственный центр» 2007
• Subjects: Keta; Magadan; Tauy; Sakhalin
• Online Access: http://cyberleninka.ru/article/n/osobennosti-formirovaniya-populyatsionno-geneticheskoy-struktury-kety-oncorhynchus-keta-na-rannih-stadiyah-ontogeneza; http://cyberleninka.ru/article_covers/12866571.png

Исследована генетическая структура молоди искусственного и природного происхождения. Наблюдение за динамикой генетической структуры кеты искусственного воспроизводства на разных стадиях ее развития позволило отметить, что на более поздних этапах онтогенеза отбор направлен в пользу гетерозигот. У заводской молоди из исследованных популяций, выращиваемой в одинаковых условиях, генетический отбор имел разные характерные особенности. Он был направлен на сохранение их исторически сложившегося генетического облика. В то же время изучение заводской молоди кеты разных стадий онтогенеза позволило обнаружить общую тенденцию к увеличению показателей генетического разнообразия по мере ее развития. Some problems of salmons artificial reproduction are caused by neglect of their genetic structure. By this reason, interplant transportation of artificially impregnated hardroe between the rivers of Sakhalin, Kuril Islands, Magadan region, and Amur basin has extremely low efficiency or even negative effect for the populations. Genetic structure of Oncorhynchus keta juveniles received from the producers from different spawning grounds is analyzed at early stages of ontogenesis for revealing the forming mechanisms in artificial environment. The character of selection among fish, collected on the same day, both alive and dead, was studied. The genetic diversity was higher in the specimens taken alive. In early ontogenesis, a selection is directed against heterozygotes, but becomes less pronounced in late ontogenesis; so, the fish have higher genetic diversity on the late stages of ontogenesis. This tendency is common for the juveniles belonged to different populations, but each population has its own features of genetic structure forming directed to preservation of their existing genetic patterns, in spite of identical conditions of the hardroe incubation and keeping of the juveniles. Besides, the juveniles of common origin raised at different hatcheries (Ola EPAB and Tauy LRZ) have different features of genetic structure, as well, that is supposedly caused by different temperature conditions of incubation. The Ola EPAB is characterized by sharp changes of the temperature between the period of hardroe incubation in July-September (7.38.8 oC) and the period of juveniles transition to active feeding in February-April (about 1.0 oC). The Tauy hatchery has stable temperature conditions. Unstable temperature conditions influence on both physiological development and genetic diversity of the juveniles making negative effect on the offspring quality and worsening their genetic abilities for adaptation in the natural habitat. The conclusion is made that conditions of keeping for artificially reproduced fish should be closely related to the natural ones for its better survival. Genetic structure of farmed fish was monitored for revealing its negative changes. The data on parental and filial generations of the artificially reproduced kulkutta population of the keta were compared. Genetic diversity of the young fish was lower than that one of the producers. In spite of high recurrence typical for artificial populations, this result is the evidence of negative genetic changes in the studied population.