Abstract:
Parameters of peroxidase complex are indicators of the adaptable processes which are taking place in plants under the environment influence. In this work the general activity dynamics and peroxidase isoenzyme composition in vegetative organs of Japanese quince (Chaenomeles Lindl.) were studied. The four species introduced in a steppe zone of Ukraine were researched: Ch. japonica (Thunb.) Lindl., Ch. speciosa (Sweet) Nak., Ch. cathayensis (Hemsl.) Schneid., Ch. × superba (Frahm) Red.). It was determined that the enzyme activity of these species possesses specific features subject to the phases of seasonal development and in response to the action of the hydrothermal stress. The highest enzyme activity in the period of intensive growth and flowering, with a subsequent sharp drop towards the middle of summer and further smoother decrease during the phase of physiological rest were observed in the leaves of Ch. speciosa and Ch. cathayensis. A higher peroxidase activity was a characteristic of Ch. japonica and Ch. × superba in the middle of the vegetative period, which can be considered a display of adaptation processes in the conditions of an unfavourable hydrothermal regime. The dynamics of changes in the quantitative composition of isoperoxidases was similar to the dynamics of enzyme activity. As a result of the generalization of the obtained data it is possible to consider that Ch. japonica and Ch. × superba are the steadiest in the conditions of the region.
