In vitro conservation and TDZ-induced micropropagation of Rhododendron yedoense var. poukhanense (H. Lev.) Nakai
Yu. G. Zaytseva
Central Siberian Botanical Garden of SB RAS, Novosibirsk, Russia
Keywords: Rhododendron yedoense var. poukhanense, germplasm conservation, in vitro seed germination, micropropagation, thidiazuron, in vitro rooting
Abstract
An effective system of Rhododendron yedoense var. poukhanense (H. Lév.) Nakai. regeneration from seedling explant based on the use of thidiazuron (TDZ) for meristem proliferation was presented. In vitro germinated seedlings were used as explants. The duration of seed germination was 24 days. The total germination of the R. yedoense var. poukhanense seeds of was at the level of 77.5 %. The effects of 4-hour TDZ pulse treatment (7.5; 15.0; 30.0 µM) with further transferring to Anderson’s medium (AM) without TDZ and direct cultivation on AM supplemented with 1.0 µM TDZ on the morphogenic potential of seedlings were studied. R. yedoense var. poukhanense regenerants obtained both after pulse treatment and after cultivation on a TDZ-containing medium ware found to require an additional passage on hormone-free AM (AM0) for elongation and an increase in the number of shoots per explant. The highest number of shoots per explant was obtained after elongation with direct cultivation on AM with 1.0 µm TDZ and after 30.0 µm TDZ pulse treatment, on average 9.32 and 10.32, respectively. The maximum percentage of rooted plants (50 %) was obtained under the action of 4-hour pulse treatment with indolyl butyric acid followed by in vitro cultivation on AM0. The presented study demonstrates for the first time the effect of various types of TDZ treatment on the proliferation and development of shoots, and the developed technology made it possible to obtain rooted and acclimatized microshoots induced by TDZ pulse treatment. As a result, R. yedoense var. poukhanense was included in the in vitro collection for conservation and propagation for further practical use.
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