Embryo culture for preserving stone fruit (Prunus L.) embryos of different cross combinations and free pollination populations

The article studies the survival capacity of stone fruit ( Prunus L.) embryos in nutrient media of diff erent mineral composition, with various growth regulators under conditions of in vitro culture. The studies were conducted in 2022-2023, with 364 initial explants in the fi rst year and 380 in the second year. Isolation of embryos of diff erent cross combinations, such as common plum ( Prunus domestica L . ), cherry plum ( Prunus cerasifera L.), apricot ( Prunus armeniaca L.), sloe ( Prunus spinosa L.), and free pollination populations was carried out between June, 21 and July, 19. The study used four modifi ed nutrient media: Murashige-Skoog (MS) (75 % of total macronutrient content) with addition of the following: 1 – 0.5 mg/L forchlorfenuron (CPPU), 2 – 0.5 mg/L indolebutyric acid (IBA) + 0.5 mg/L indolylacetic acid (IAA); Quoirin and Lepoivre (QL,) with the addition of: 3 – 0.5 mg/L CPPU, 4 – 0.75 mg/L IBA + 0.75 mg/L IAA. The results indicate the feasibility of using both MS with diluted mineral part of macronutrients up to 75 % (from total amount) and QL for preserving embryos of intraspecifi c and interspecifi c hybrids of stone fruit crops. Moreover, at the stage of isolating embryos the use of nutrient media MS with diluted mineral part of macronutrients up to 75 % (of full content) and QL provides obtaining of high-quality isolated explants of stone fruit crops ( Prunus L.). At that, the survival capacity was higher on the QL nutrient medium in case the parental forms included the cherry plum variety Kubanskaya Kometa . In the majority of Prunus L. cross combinations, a higher (up to 100 %) frequency of initial embryo development was achieved by adding 0.5 mg/L CPPU to nutrient media (regardless of mineral composition). Therefore, it is advisable to use both MS-based and QL-based media in equal proportions to obtain over 33 % of developed embryos while initiating stone fruit embryos of controlled cross combinations and free pollination populations into in vitro culture.