Env Exp Biol (2014) 12: 143–147

Attempted genotype-independent induction of shoots in 15 carnation (Dianthus caryophyllus) cultivars from four explant types

Abstract

Plant growth regulators were used in an attempt to directly induce adventitious shoots in 15 carnation (Dianthus caryophyllus L.; Caryophyllaceae) cultivars: ‘Orange Sherbert’, ‘Avalanche’, ‘Magenta’, ‘La France’, ‘Stripe Red’, ‘Marie’, ‘Concerto PVP’, ‘Snap’, ‘Lucky Pierot’, ‘Cinnamon Tea’, ‘White Love’, ‘Siberia’, ‘Magesta’, ‘Spark Bruno’, and ‘Honono no Estejo’. After sowing seeds on top of autoclaved moistened filter paper, internodes between nodes 1 to 4 from the apical meristem were surface sterilized and induced to form shoots in the presence of 1 mg L^–1 thidiazuron (TDZ) and 1 mg L^–1 α-naphthaleneacetic acid (NAA) on basal Murashige and Skoog (MS) medium. Shoots were excised from mother explants and subcultured on Hyponex® (N-P-K = 6.5-6-19) medium containing 30% (w/v) sucrose to establish in vitro stock cultures, which was possible for all 15 cultivars. After two sub-cultures to eliminate the possible influence of seed-derived heterogeneity, internodes, transversal thin cell layers (tTCLs) from internode tissue, nodes and leaves from nodes 1 to 4 of one-month-old stock plantlets were excised and placed on MS basal medium containing 0, 1, 2, 4 or 8 g L^–1 2,4-D, TDZ, kinetin (Kin) or 6-benzyladenine (BA), together with 0, 0.5, or 1.0 mg L^–1 NAA. Shoots formed best in the presence of 1 mg L^–1 TDZ and 0.5 mg L^–1 NAA from all cultivars. Callus, which was induced in the presence of BA, Kin and 2,4-dichlorophenoxyacetic acid, was not quantified. Results from all 15 cultivars were pooled: the largest number of shoots formed from nodes (4.85 per explant), although many more shoot initials formed. Internode tissue and tTCLs performed poorly. Individual shoots one-cm long excised from explants rooted easily (100%) in Hyponex® medium. This study provides a relatively effective and almost genotype-independent protocol for the establishment of carnation in vitro cultures.