Microgram-grade concentration of chlorine dioxide induces one-step plant regeneration in chrysanthemum

Efficient in vitro regeneration of chrysanthemum requires virus-free plants for production. Previous studies have employed various exogenous plant growth regulators (PGRs) to induce shoot and root growth. Here, this study reports an efficient one-step regeneration protocol for chrysanthemum through incorporating a 10 μg L −1 chlorine dioxide (ClO 2 ) solution into a medium; this method was compared with the previously reported PGR-mediated regeneration and the PGR-free medium (control). The results showed that the use of 10 μg·L −1 ClO 2 achieved one-step regeneration of chrysanthemum by simultaneously inducing the growth of roots and shoots within 3 wk. Transplanting survival reached 100%. The ClO 2 -induced regenerants showed greater axillary buds, biomass, root number, and root length compared with the control and PGR treatment ( P 95% molecular fidelity in ClO 2 -induced regenerants similar to the PGR treatment. Reverse transcription-polymerase chain reaction indicated that 10 μg·L −1 ClO 2 is equivalent with known PGRs in the propagation of virus-free chrysanthemum plantlets. Moreover, higher or equivalent chlorophyll content, root vigor, and total flavonoids were observed in ClO 2 -induced regenerants compared with the PGR treatment. This protocol would facilitate large-scale micro-propagation of chrysanthemum plantlets.