Determinants of the reproduction of Рrunus dulcis (Mill.) D.A.Webb. biotechnological methods

Abstract

The purpose of the presented article is to establish the trophic and hormonal determinants of the ontogenesis of Prunus dulcis regenerants in vitro. One of the urgent problems in Ukraine is climate change, which reduces the level of achieving sustainable development and hinders humanity from both agroecological and food security. Such changes lead to the diversification of traditional agriculture. In Ukraine, almonds are a valuable, promising nut crop, thanks to which it is possible to diversify climate risks. Varieties of foreign selection with a long growing season and low winter hardiness are not suitable for our zone. Plants of four domestic varieties of almonds E5 Borozan, M41 Alex, Georgia, Louise (entered into the register in 2020) were involved in the study. One of the reliable methods for obtaining high-quality planting material, healthy from diseases, fast reproduction rates is microclonal reproduction. Therefore, modern nurseries switch to the production of planting material using biotechnological methods. Preparatory measures of mother plants of explant donors and decontamination increase the efficiency of work at the first stage of microclonal propagation. Primary explants are planted on media with a twice-reduced content of nutrients and a high content of cytokinins and gibberellins. Its success also depends on the selection of components, the pH of the nutrient medium (trophic determinants), and the interaction of exo-genous and endogenous hormones (hormonal determination.) The main trophic determinants are synthetic carbohydrates and mineral components added to artificial nutrient media. According to the Skoog-Miller rule, at the stage of multiplication, cytokinins predominate in the nutrient medium, and for root formation, their content decreases and the content of auxins decreases. Both auxins and cytokinins are added in high concentrations to stimulate callus formation. A systematic study of the features of the determinants of microclonal reproduction of almonds is relevant for the creation of MCR technologies. The lack or unavailability of one of the elements affects the plant object. Key words: microclonal reproduction, almonds in vitro, power elements, synthetic phytohormones.