Kotsar M. Evaluation and selection of source material for breeding miscanthus by biotechnological methods

The thesis is devoted to the development of principles for the breeding of genotypes of miscanthus tolerant to drought and salinity based on biotechnology methods and their effectiveness in open soil. The method of clonal micropropagation of miscanthus based on the selection of sterilizing reagents, their exposures and the addition of different concentrations of cytokinins and auxins in the nutrient medium has been improved. The issue of the reaction of miscanthus shoots in vitro to abiotic stresses (drought and salinity) is covered. The optimal concentrations and exposures of the effects of stress factors of mannitol and salts on the viability and shoots formation development of explants of various genotypes in vitro were determined. The scale of estimation of the degree of miscanthus tolerance to the abiotic factors in vitro which takes into account the complex parameters of physiological state is developed, which allows to simplify the selection of sources of tolerance to certain abiotic stresses. The biomorphological parameters of the reaction of miscanthus which were selected on selective nutrient medium to the effect of different moisture content of the soil and salt stress in the vegetative experiment were investigated. The content of chlorophylls a and b, dry matter and changes in the activity of oxidoreductase (catalase and peroxidase) in miscanthus shoots in vitro and grown in the field under the influence of stress factors have been estimated, which allows them to be used as a test sign of tolerance to drought and salinity in miscanthus. The survival of miscanthus was established when transferred from in vitro in open soil for preliminary adaptation in greenhouse and in open soil, in which the optimal method of their transfer was chosen. The terms of revealing of the bioenergy potential of miscanthus according to the anatomical and morphological parameters were established. The elements of the structure of biomass yield and energy output in different species of miscanthus in the field are determined. Prospective for commercial use miscanthus species (M. giganteus and M. sinensis) with a combination of tolerance to abiotic stresses and high energy output are selected. Keywords: miscanthus, biotechnology methods, tolerance, abiotic stress, biomorphological, physiological and biochemical parameters, energy output.