106(2)_str22

 

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 106, No. 2 (2019), p. 167–172
DOI  10.13080/z-a.2019.106.022

Role of phytohormones in the formation of dwarf and tall Siberian crabapple (Malus bаccata L. Borkh.)

Alexandr V. RUDIKOVSKII, Alexandra V. STOLBICOVA, Elena G. RUDIKOVSKAYA, Luybov V. DUDAREVA

Abstract

Peculiarities of hormonal status of dwarf and winter hardy trees of Siberian crabapple (Malus baccata L. Borkh.) were studied. The research was carried out on plants growing in the natural habitat (western Transbaikalia, 2009–2010) and in a cultivated orchard (Irkutsk city, 2012–2013). The study showed that dwarfism is caused by a decline in indole-acetic acid (IAA) content and by the associated changes in the IAA:ABA (abscisic acid) content ratio in the crabapple plants in both growing conditions. During the experimental period, this ratio was above and below unity for tall and dwarf trees, respectively. The content of phytohormones remained unchanged in the studied forms in the cultivated orchard despite the increase in the growth rate of scions. It was concluded that the IAA content depended on the synthesis of the acid in the above-ground part of plants. In this context, the contribution of phytohormones to the formation of the dwarfism of M. baccata was discussed. We believe that the combination of winter hardiness and dwarfism in these trees make them very promising as parental forms for breeding resistant rootstocks.

Key words: abscisic acid, dwarf forms, indole-acetic acid, Malus bаccata, phytohormones, Siberian crabapple.

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