Conservation of six threatened tree species of Georgia by in vitro propagation
The conservation of plant biodiversity is an important issue concerning the human population worldwide. Advances in plant biotechnology provide new options for collection, multiplication and conservation of plant biodiversity using in vitro culture techniques. Many unique representatives of Georgian flora are threatened by extinction and/or genetic pollution due to negative impact of various environmental and anthropogenic factors. In these experiments the attempt was made to establish viable regeneration procedures for 6 broad-leave species included in Red List of Georgia, Castanea sativa Mill., Amygdalus georgica Desf. (Prunus tenella Batsch.), Betula raddeana Trautv., Betula megrelica Sosn., Betula medwedewii Regel., Populus euphratica Oliv., using in vitro seedlings, zygotic embryos and axillary buds as initial explants. The effects of N6-6-benzylaminopurine (BAP), kinetin and indole-3-butyric acid (IBA) added to Murashige and Skoog medium (MS) and woody plant medium (WPM) were tested on organogenesis. All plants showed the better initiation and multiplication rates in WPM medium. The highest number of shoots from axillary buds (11.5) and zygotic embryos (9.6) were obtained for P. euphratica and A. georgica on WPM medium supplemented with 1.1 and 2.5 µM BAP respectively. Less effective shoot multiplication was shown for C. sativa (1.8) in all media with 20% of survival. The optimal medium for in vitro rooting of shoots was WPM medium containing 1 µM IBA for Betulaceae showing highest rooting frequency (93-98%) and survival rate (95-100%). P. euphratica and A. georgica showed the better rooting in WPM medium (65% at 0.5 µM IBA and 46% at 15 µM IBA, respectively). For acclimatization rooted plants were transferred to plastic cups filled with mixture of perlite (sphagnum peat: perlite) at the ratio 2:1. Feasibility of in vitro propagation protocols of woody perennials will likely contribute to better approaching over vegetative multiplication and in situ conservation of rare and threatened tree species.
Gaidamashvili, M., Khurtsidze, E. and Khechoshvili, V. (2017). Conservation of six threatened tree species of Georgia by in vitro propagation. Acta Hortic. 1187, 189-198
in vitro culture, axillary buds, zygotic embryos, Amygdalus, Betula, Castanea, Populus