Influence of concentration and formulation of macrosalts in the nutrient medium on the indicators of meristem regeneration at the stage of introduction to culture in vitro in some aboriginal Don grapes varieties

Abstract. Rare indigenous grape varieties are of significant value for viticulture, breeding and preservation of genetic material. Often, ancient grape varieties, due to prolonged vegetative propagation, are infected with one or more chronic diseases (viruses, phytoplasmas, bacterial cancer). The most reliable way to improve the health of such plants is the method of apical meristems in in vitro culture. In which, on artificial nutrient medium, it is necessary to regenerate the plant from isolated extremely small apical explants (about 50-100 microns). One of the most important components of nutrient medium are macroelements. Not only their quantity is of great importance, but also the compounds they represent, as well as the balance and ratio of all elements in the nutrient medium. In this regard, the purpose of our study was to study the characteristics of mineral nutrition of grape plants of native Don varieties in in vitro culture. To do this, we studied the effectiveness of the most commonly used nutrient media in microclonal propagation. The experiments were carried out on four rare native Don varieties Plechistik oboepolyi, Bessergenevskiy №10, Musketnyi and Durman. Protocols used: Murashige and Skuug (MS), McCown Wood Plant (WPM), Chee and Pool (C2D), Quoirin & lepoivre (QL) and Anton Rebrov (AR1). The nutrient media differed only in the composition of macrosalts; all other components were added in equal quantities. The varietal response of the studied varieties was different. The Plechistik oboepolyi and Bessergenevskiy №10varieties regenerated best, and the Musketnyi and Durman varieties regenerated more poorly. It has been established that the composition of macroelements significantly affects the regeneration and differentiation of shoots in apical meristems. For most varieties, the most stable results were observed when using WPM and AR1 nutrient media. The worst development of explants in all varieties in the study occurred on MS and C2D media. Key words: apical meristem, introduction into in vitro culture, regeneration of explants, recipes for nutrient media, concentration of macronutrients, native Don varieties