Biotechnological and molecular genetic methods in grape breeding

The development of new grape varieties with improved quality and resistance against environmental factors using biotechnological methods is a pressing task in the context of import substitution policy implementation. Due to the high heterogeneity of grape varieties, techniques for regenerating plants from embryogenic callus by somatic embryogenesis have been developed only for a small number of genotypes. This work presents a versatile approach to the development of globular, heart, and torpedo embryos in various grape genotypes. Experiments were carried out using cultures of colchicine embryogenic cell suspensions and somatic globular embryos of the E-342 hybrid form in liquid media. The developed methodology allows the protocols of embryogenesis and polyploidy induction to be effectively improved. The versatility of the presented methodology for polyploidy induction and somatic embryogenesis in grape plants is ensured by a fourfold reduction in the concentration of inorganic nitrogen and vitamins in the NN and PG media and the addition of organic nitrogen and other biological active substances at the stages of embryogenic callus development, colchicination, and development of somatic embryoids in liquid media. The methods of indirect ploidy determination by the properties of the grape leaf epidermis were studied and implemented. Nine promising somaclones were preliminary selected based on a set of four features. It was established that full-fledged transgenic grape plants can only be obtained by the method of transformation, which involves the production of embryogenic callus from a leaf explant, its subsequent passage into a liquid culture to obtain a liquid embryo culture, and the transformation of this culture. In total, 300 leaf explants of the Libya variety and 1 100 globular embryos of the Podarok Magaracha variety were transformed. As a result, six callus kanamycin-resistant lines of the Libya variety and six lines of transgenic plants of the Podarok Magaracha variety were selected. Following genotyping based on nine nuclear microsatellite loci, seven unknown forms with a seedless phenotype were identified. Among the population of hybrid seedlings, hybrids having alleles associated with seedlessness were revealed using the VMC7f2 and p3_VvAGL11 MAS markers.