World experience and prospects of hazelnut and almond breeding in Ukraine

Abstract

Hazelnuts and almonds are promising industrial crops that can differentiate the risks posed by climate change. Domestic almond varieties adapted to local conditions have been created in Ukraine, which require rapid propagation. Creating highly productive and disease-resistant varieties of hazelnuts also requires the reproduction of this crop in signifcant quantities. Of all the methods of vegetative propagation microclonal is the most promising one. Prior to introduction into aseptic culture, mother plants are grown in conditions that minimize endogenous accumulation in tissues of contaminants and phenolic substances. Sodium hypochlorite and Blanidas 300 are used for decontamination of explants. The addition of PPM biocide to the nutrient medium is promising to improve the sterilization of hazelnut explants. The decrease in contamination of almond explants decreases with increasing concentration of Cu, Ag ions in the environment. Mineral nutrients and phytohormones are hte main determinants of in vitro ontogeny. Along with the classic media (DKW, QL, MS, WPM) NRM environment is promising for hazelnuts, and NAM environment – for almonds. Excess in the environment of some elements reduces the assimilation of others, which is manifested visually. Thus, an excess of nitrogen causes symptoms of insufcient absorption of calcium, copper. This process is intensifed as the temperature increases. In addition, regenerating shoots are shortened, thickened and have excessive tissue hydration. Turkish scientists have proposed an original method of creating recipes for almonds and hazelnuts on the quantitative content of elements in the seeds of these plants. Cytokine are the most common phytohormones at the multiplication stage. For both cultures, most researchers prefer benzylaminopurine. Indolylbutyric acid is most often used to induce rhizogenesis. A perlite-based substrate is effective for the regenerants adaptation. It is suggested to inoculate regenerants on bitter almond seedlings as a type of adaptation. A method of photoautrophic microclonal propagation has been developed in Ukraine. These technological methods, which, along with vegetative propagation, allow the adaptation of regenerants in a short time. The efciency is achieved by activating the processes of photosynthesis due to increased carbon dioxide content and light intensity. Key words: hazelnuts, almonds, climate change, microclonal reproduction, determinants, nutrient media, phytohormones.