Drought resistance of new varieties and forms of ornamental peach

Abstract

The drought resistance parameters of 11 new genotypes of ornamental peach were determined for their further breeding and use in ornamental horticulture. These genotypes were hybrids of Prunus mira, P. davidiana, and P. amygdalus with P. persica, as well as P. mira with P. amygdalus. The impact of hydrothermal stress on plants was assessed under the conditions of the Southern Coast of Crimea during 2021-2023 after the maximum manifestation of stress factors. The research was carried out using a fi eld method of visual assessment and laboratory determination of water-holding capacity and restoration of leaf turgor after dehydration. The fi eld assessment of drought resistance of ornamental peach ranged from 3.5 to 4.7 points. Most genotypes retained a good appearance and showed minimal losses of the leaf system. The total water percentage in the leaves of the studied genotypes ranged from 53.3 to 71.7 %. Water defi cit in leaves was signifi cant in some cultivars, fl uctuating within the range of 10.8-33 %. The least signifi cant water defi cit of up to 16.7 % was characteristic of 37.5 % of the genotypes. It was experimentally established that during 4 hours of wilting, the leaves of the studied samples lost from 8.2 to 45.9 % of water. The losses amounted to 14.6-50 % after 8 hours, and 18.5- 57.1 % after 12 hours. The leaf dehydration during 24 hours were almost critical for 60 % of the cultivars, since they lost 38.1-61.5 % of water. The lowest losses (26.2-33 %) were observed in six genotypes. Despite prolonged hydrothermal stress, 62.5 % of varieties and forms demonstrated a very high leaf recovery capacity (80.1-99.2 %). The NP6-5/1, NP6-16/1 hybrids, and the ‘Rozovolikiy’ variety demonstrated the highest water-retaining capacity combined with a high reparative capacity of leaves after dehydration. The NP6-5/1 hybrid was characterized by a combination of the highest drought resistance parameters. In addition, ‘Milashka’, NP6-21/1, NP6-16/3, NP6-2/1 varieties and forms with a high degree of leaf reparation and drought resistance are recommended for further breeding and testing in landscaping