Innovative technologies for cloned plants adaptation

Abstract

Chrysanthemum plants are popular with amateur gardeners and breeders. It is widely used in landscaping cities, parks, and also for bouquets. Plants are notable for longer flowering and a bright color of flowers. Extracts of chrysanthemum plants contain various biologically active substances with bactericidal properties and are used in pharmacology and dentistry. The objective is to develop an effective technology for rapid in vitro reproduction and adaptation of chrysanthemum microclones. The objects of the study were chrysanthemum plants of three varieties: Bacardi, Korean Dawn, and Snow White. Semifloscules and flower buds were used as primary explants. The explants were cultured on a Murashige and Skoog (MS) nutrient medium containing mineral salts, as well as various growth regulators: 1) 1 mg L-1 BAP + 0.5 mg L-1  IAA; 2) 15% Aminoven solution 3 mL L-1 ; 3) Stimul 1 mL L-1 ; and 4) a hormone-free medium. Microshoots were adapted using an aeroponic system. Unrooted microshoots were used for adaptation. The GrowPlant X-Stream 120 propagator was used as equipment for adaptation. The frequency of adventious budding depended on the hormonal composition of the nutrient medium. Aminoven in the nutrient medium led to the induction of the formation of adventitious buds on average in 85% of cases. The same indicator averaged 72% on the Stimul-containing medium. In a BAP-containing medium, the considered indicator was the same with the control variant (hormone-free medium). The Snow White explants had the highest regenerative activity, Bacardi was second, and Korean Dawn was third. Studies have shown that the efficiency of adaptation of unrooted microshoots under aeroponic conditions is significantly influenced by the composition of the nutrient medium during micropropagation. Thus, preliminary cultivation of microshoots in vitro on Stimul and Aminoven-containing media led to the rapid formation of the root system and active growth of the aerial part. In these variants, the shoot growth index (I) was 0.65-0.71, and specific rate (µ) was 0.89-1.1 mm day-1.