Notice of RetractionEstablishment of Embryogenic Cell Suspension Cultures and Doubling the Chromosome Number by Colchicine Treatments in Purple Coneflower

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

Cell suspension cultures of purple coneflower (Echinacea purpurea L.) were established by inoculating petiole explants into liquid medium containing MS salts, B5 vitamins, 3% sucrose, 1 mg/l IBA, and various concentrations of TDZ and sorbitol. Results of the experiments indicated that 0.1 mg/l TDZ in combination with 3% sorbitol was most effective for the induction of embryogenic calluses. These embryogenic calluses were induced to regenerate plants after being treated with 60 mg/l colchicine for various durations in liquid medium. It was found that calluses treated with colchicine for 4 days yielded the largest number of tetraploid plantlets. Because embryogenic calluses proliferated fast and had high plant regeneration potential, this suspension culture system can be used for micro-propagation of some elite genotypes, and the tetraploids obtained in the present study can serve as valuable materials for various breeding program.