Features of obtaining an aseptic culture of Prunus dulcis (Mill.) D.A. Webb.

Abstract

The purpose of the presented article is to establish the features of obtaining an aseptic culture of regenerants of Prunus dulcis in vitro. Since the impact of climate change is becoming increasingly large-scale in Ukraine, one of the urgent problems that hinders humanity, both in terms of agro-ecology and food, is the need to diversify traditional agriculture. Mydal is one of the valuable promising nut crops in Ukraine, thanks to which it is possible to diversify the climatic risks listed above. The varieties of domestic selection were taken for experiments, since foreign selection with low winter resistance and a long growing season are not suitable for our zone. Four intensive new varieties of almonds E5 Borozan, M41 Alex, Georgia, Louise, which were bred by breeder V.M. Babanskyi and entered into the State Register of Plant Varieties, and allowed in Ukraine for cultivation. One of the reliable methods of reproduction is microclonal reproduction, with the help of which it is possible to quickly obtain high-quality, disease-free planting material. Therefore, for the production of planting material, modern nurseries are switching to biotechnological methods. It was established that the preparation of explant donors reduces the number of primary explants that released phenolic substances. In addition to the preparation of donors, nutrients, which were present in different amounts in nutrient media with different composition, had a significant impact. The fewest explants with phenol-like exudate were on NAM and NRM media.Common to these two environments is a relatively low content of nitrogen in both ammonium and nitrate forms, and the DKW environment contains the highest amount of sulfur. The release of phenol-like exudate also depended on the biological characteristics of almond varieties. The highest number of primary explants was in the high-growing variety E5 Borozan, and the least in the variety Louise with medium growth intensity. Depending on the variety, 81–91 % were free from contaminants in the depository, while 59–70 % were in control. Morphogenic and at the same time without signs of contamination were found from 69 % among the explants of the Louise variety and up to 73 % of the E5 Borozan variety, compared to 35 and 51 %, respectively, in the control. Based on the results of the research, it was established that the influence of the time of isolation of the primary explants and the features of the interaction of the plant and its surrounding microbiota in different seasons are different. This is manifested in the features of contamination by these objects of primary explants and, accordingly, the success of decontamination (E1) and the appearance of microbiological contamination on the nutrient medium. Key words: microclonal propagation, nut crops, multiplication, morphogenesis, contaminants, decontamination.