The Establishment of a Highly Efficient In Vitro Regeneration System for Viburnum opulus L. 'Roseum'

Viburnum opulus L. 'Roseum' is a highly valuable ornamental plant for landscaping, but it has a long propagation cycle and low propagation coefficient. In this study, stem segments with axillary buds from Viburnum opulus L. 'Roseum' were used as explants. We systematically analyzed the use of sodium hypochlorite for the sterilization of explants, as well as the effects of different plant growth regulator combinations and concentrations on shoot bud induction, shoot proliferation, the rooting of tissue-cultured shoots, and the transplanting of the tissue-cultured shoots. A complete rapid propagation technology system for Viburnum opulus L. 'Roseum' was established. The results showed that a disinfection method using 75% ethanol for 30 s and soaking in 5% sodium hypochlorite for 5 min was the most suitable for disinfecting the stem segments of Viburnum opulus L. 'Roseum', which showed low contamination and a 73.33% survival rate. The ideal medium for primary bud induction was WPM (Woody Plant Basal Medium) + 2.0 mg·L^-1 6-benzylaminopurine (6-BA) + 0.15 mg·L^-1 indole-3-butyric acid solution (IBA) + 25 g·L^-1 sucrose. The optimal medium for shoot proliferation was WPM + 1.0 mg·L^-1 6-BA + 0.15 mg·L^-1 IBA + 25 g·L^-1 sucrose, achieving an induction rate of 7.17. For the rooting of tissue-cultured shoots, the most suitable formulation was 1/2 WPM + 0.3 mg·L^-1 naphthaleneacetic acid (NAA) + 0.3 mg·L^-1 activated charcoal (AC) + 25 g·L^-1 sucrose, which induced robust and developed root systems. This study provides a technical basis for the establishment of a fast propagation system for the industrial production of Viburnum opulus L. 'Roseum'.