Features of canna regeneration in vitro and plantlets adaptation in vivo

Using in vitro culture for propagation of canna (Canna × hybrida hort.) gives us the possibility to rapidly multiply virus-free stock plant material. We have studied features of in vitro regeneration ability and in vivo adaptation of 3 canna cultivars ('Dar Vostoka', 'Livadia', 'Suevia'), grown at the collection plot of Nikita Botanical Gardens (NBG). Surface-sterilized vegetative buds were cultured on solidified half-strength Murashige and Skoog (1962) medium (MS), supplemented with cytokinins (thidiazuron NDASH TDZ, 6-benzylaminopurine NDASH BAP) and auxins (3-indoleacetic acid NDASH IAA, 1-naphthalene acetic acid NDASH NAA). Adventitious shoot formation on the MS medium with 1.24-1.91 mg L^-1 TDZ has been shown for all the tested cultivars. The multiple meristemoids have been regenerated at the base of adventitious microshoots after its separation and subculture on a fresh medium. After 6-7 months, 20 and 40 meristemoids (size 0.1-0.7 cm) per explants have been formed for each cultivar. To regenerate the plants, the meristemoids were placed on the MS medium supplemented with 2-4 mg L^-1 BAP or 1.5 mg L^-1 BAP and 1.5 mg L^-1 IAA. 100% of 'Suevia' microshoots rooted on MS medium with 1.25 mg L^-1 IAA or 1.5 mg L^-1 NAA. The regenerants with 2-3 leaves and 5-6 roots have been transplanted to adaptation in vivo. At the beginning of the adaptation 'Suevia' plantlets demonstrated a higher survival ability in vivo compared to regenerants of 'Livadia'. The best results of adaptation have been reached due to the apply of a mixture of leaf mold and agroperlite (survival NDASH 75%), compared with simply perlite (50%). Investigation of morphoanatomical structure of leaves and redistribution of fractional water composition has showed an adaptability in vivo of regenerated 'Suevia' and 'Livadia' plantlets.