Tkachova Y. Cytogenetic effects in seed germs of Pinus pallasiana D. Don and Picea abies (L.) Kаrst. from stands in industrial regions of the steppe zone of Ukraine

This work is devoted to the study of cytogenetic effects observed in the cells of seed progeny of Pinus pallasiana D.Don and Picea abies (L.) Karst. in adverse environmental and climatic conditions of the steppe of Ukraine. It is established that there is a significant number of abnormalities of the structure of chromosomes, spindle integrity and loss of genetic material in P. pallasiana seedlings cells under the technogenic conditions. There were detected micronuclei in seedling cells from all investigated samples that is indicative of pathological processes in the course of seed formation. A significantly lower level of violations was observed in this species under the conditions of introduction in the steppe of Ukraine. There were no peculiar features of the mitotic processes in Picea abies related to growth conditions. A pronounced trend of increase in the total length of a chromosome set and number of secondary constrictions was revealed in the karyotype of both plant species in plantations. Poikiloploid plant seedlings were detected in Picea abies in the Arboretum of the Donetsk Botanical Garden. Their presence can be related to adaptive responses. There was noted an increase of nucleoli number per nucleus and that of nucleoli structures' size in the investigated seedling cells of maternal plants growing in adverse conditions. The opposite trend was observed in nucleus-nucleolus ratio change for these two species. A marked decrease in this index was noted in P. abies plantation, whereas its increase was characteristic of P. pallasiana.