The establishment of effective regeneration system and in vitro culture of Campanula

摘要

Several species of Campanula genus have been cultivated as ornamental plants, and there is an increasing demand for more attractive and novel characteristics. Optimal regeneration protocol is prerequisite for subsequent successful genetic manipulationand generation of new features. In the current study, the optimal media composition and explant source for shoot regeneration of three Campanula cultivars, C. portenschlagiana 'Blue Ocean' (BO) and 'Royal', C. carpatica 'Improved Blue Uniform' (IBU) were determined. The focus of this study was based on avoiding an over-supplementation of plant growth regulators (PGRs), especially the cytokinin thidiazuron (TDZ). The explants examined for shoot regeneration were petioles harvested from two different explant sources: 1) petioles of 3-month-old tissue-cultured plants, 2) petioles of etiolated nodal cuts. To find out the best media composition for shoot regeneration, different naphthalene acetic acid (0.5,1.0 and 2.0 mg L1) and TDZ (1.0, 2.0, 3.0 and 5.0mg L1) concentrations were investigated. According to the results, the most favourable explant source for harvesting petioles were etiolated nodal cuts of mature greenhouse plants. The best shoot regeneration obtained from the harvested petioles of nodalcuts in the 3 cultivars were 85% in IBU, 65% in BO and 45.8% in 'Royal'.