Академическое издательство «Гео»

Key words: Rhododendron, direct regeneration, floral explants, thidiazuron.

Rastitel'nyj Mir Aziatskoj Rossii (Plant Life of Asian Russia), 2017, № 4, p. 66-72

In vitro propagation of some frost-resistant genotypes of genus

Yu.G. Zaytseva, T.I. Novikova

Central Siberian Botanical Garden, SB RAS,
630090, Novosibirsk, Zolotodolinskaya str., 101, e-mail: ulianna_zaitseva@mail.ru

The efficient systems of in vitro establishment and direct shoot regeneration from floral explants of frost-resistant genotypes of Rhododendron L. genus promising for landscaping and breeding (semi-evergreen species R. sichotense Pojark. and evergreen cultivar ‘Pohjola´s Daughter’) were developed. The isolated pistil with pedicle was used as a floral explant. The effects of various thidiazuron (TDZ) concentrations and TDZ combinations with 2-isopentiladenin (2-iP) and indolyl-3-butyric acid (IBA) as well as with zeatin were tested. The regeneration occurred directly from pedicle tissues. The study revealed the genotypic differences between morphogenic responses of ‘Pohjola´s Daughter’ and R. sichotense floral explants. To induce the regeneration from ‘Pohjola´s Daughter’ floral explants, the optimum medium was Andersen’s medium (AM) supplemented with 2.5 μM TDZ in combination with 73.8 μM 2-iP and 15.0 μM IBA whereas the presence of 1.0 μM TDZ was sufficient for R. sichotense regeneration. The maximum of shoots per explant obtained when explants culturing on optimum composition of AM amounted to 26.21 ± 5.26 for ‘Pohjola´s Daughter’ and 17.40 ± 3.07 for R. sichotense. The developed clonal micropropagation protocols based on the direct shoot regeneration from floral explants R. sichotense and ‘Pohjola´s Daughter’ can be used for genetic resources conservation, breeding program development and commercial large-scale propagation.

Key words: Rhododendron, direct regeneration, floral explants, thidiazuron.

DOI: 10.21782/RMAR1995-2449-2017-4(66-72)