The effect of bioballistics on the regeneration and growth of Populus tremula L. from callus tissues

This study investigates the impact of employing a gene gun for the delivery of genetic constructs on the regeneration and growth process of Populus tremula L. from callus tissues. The primary objective is to analyze the efficacy of the biolistic method as a tool for genetic modification of plants while maintaining their viability. The subjects of the study were aspen clones from the collection of the Saint Petersburg Forestry Research Institute, preserved in an in vitro microshoot culture. The research encompasses several key stages: obtaining callus cultures of aspen clones, preparing callus samples for bombardment with microcarriers containing the editing construct, initiating organogenesis from callus structures post-bioballistics, and rooting and adapting plants to ex vitro conditions. A significant aspect was analyzing issues related to bacterial contamination of callus cultures during bombardment with tungsten microcarriers. Optimal temporal parameters for callus bombardment, as well as for the adaptation of regenerants and their subsequent transplantation into a summer-type greenhouse, were established. A comprehensive assessment of the impact of bioballistics on the regeneration process of aspen from callus structures was performed. The results indicate that 70 % of regenerant plants successfully adapted to ex vitro conditions. This demonstrates that the application of the biolistic method for delivering genetic constructs into callus cells does not affect the adaptation processes of aspen to ex vitro conditions. As a result, a collection of containerized aspen seedlings with a modified genome segment has been created. This success opens new opportunities for the application of genetic engineering in breeding and improving the characteristics of forest plants.