BIOTECHNOLOGICAL AND MOLECULAR METHODS IN THE STUDY OF THE GENUS ACTINIDIA LINDL. REPRESENTATIVES

The proposed literature review analyzes various aspects of biotechnological and molecular genetic research directions for the genus Actinidia Lindl. representatives. It is shown that despite the genetic diversity of actinidia, which provides a huge potential for improving the economic and biological indicators in cultivars, there are certain biological features (including a strong shoot growth, 3–5-year juvenile period, diclinous nature and polyploid structure), which are often an obstacle to achieving certain breeding goals compared to many other agricultural crops. Since the dioecism and polyploidy in actinidia often limit the possibility of reproduction, somatic hybridization can help to overcome interspecific incompatibility in order to obtain valuable material with desirable traits from two species. Data on the developed methods for isolation of protoplasts from callus, suspension cultures, leaf mesophyll and cotyledons of various Actinidia genotypes are also presented. Special attention is paid to cell culture, tissues and organs in vitro, which is an important method in plant biotechnology, and is effectively used for clonal micropropagation of actinidia cultivars and species. The paper shows a determining value of species features in the realization of morphogenetic potential and presents optimal nutrient media and concentrations of growth regulators at all stages of micro-reproduction. The results on molecular markers used to study the genetic characteristics of the genus Actinidia representatives have also been analyzed. The data shows that most of the early studies in molecular marking were primarily aimed at researching the phylogeny of Actinidia species, which generally corresponds to the traditional classification based on morphology. Initial studies were still focused on sex determination, and therefore, molecular markers confirmed that the diclinous nature of actinidia is a consequence of sex-determining genes localized on a pair of chromosomes. Also, molecular markers have made it possible to improve germplasm, systematically crossing plants selected based on their intra- and interspecific phylogenetic relationships and types of allelic diversity, and selecting parent plants with desirable alleles.