Breeding and rapid propagation of Primulina: a pioneering example of Chinese floral innovation and commercialization

Tissue culture technology, as an efficient method for plant propagation, holds significant importance for the development and promotion of new cultivars. In this study, we established an efficient tissue culture system for two newly bred hybrid Primulina cultivars: Primulina 'Spring of Beilin' and Primulina 'POP Corn', using leaf explants. The system included explant sterilization, adventitious bud differentiation, shoot proliferation, rooting, and transplantation. The results demonstrated that the optimal tissue culture system for Primulina 'Spring of Beilin' was as follows: explants were sterilized with 75% ethanol followed by disinfection in 2% NaClO solution for 3 min, achieving a survival rate of 95.57%. The optimal induction medium for adventitious bud differentiation and shoot proliferation was MS + NAA 0.1 mg/L + 6-BA 0.5 mg/L, resulting in an induction rate of 95.59% and a propagation coefficient of 14.33. The best rooting medium was 1/2 MS without plant growth regulators, with a transplant survival rate of 100%. For Primulina 'POP Corn', explants were sterilized with 75% ethanol and disinfected in 2% NaClO solution for 6 min, resulting in a survival rate of 88.89%. The optimal induction medium for adventitious bud differentiation and shoot proliferation was MS + NAA 0.1 mg/L + 6-BA 1 mg/L, achieving a 100% induction rate and a propagation coefficient of 17.33. The optimal rooting medium was 1/2 MS + IBA 1 mg/L, with a transplant survival rate of 100%. This study established efficient tissue culture systems for two hybrid Primulina cultivars, directly inducing adventitious buds without callus formation, and shortening propagation cycles. Using ethanol and NaClO for sterilization showed simplicity and non-toxicity for large-scale production, supporting large-scale propagation, and commercialization of Primulina cultivars.