Evaluation of European native bluebells for sustainable floriculture

Most traditional flowers grown commercially today are the result of many years of intensive selection and breeding of exotic species. Relatively few European native plants have been the focus of rigorous improvement programs even if locally more suitable and available. Campanula genus comprises about 300 herbaceous species mainly distributed in the Mediterranean basin. Among these, about 50 species are widely diffused in Italy. The present research investigated the ornamental characteristics and the suitability to be cultivated of five Campanula species (C. barbata L., C. latifolia L., C. rapunculoides L., C. spicata L. and C. trachelium L.) in order to evaluate their possible introduction in floriculture as garden plant, pot or cut flower. Besides, a collection comprising 102 cultivars of 31 different Campanula species was established. Seed germination attitude was assessed by using different substrates (3:1 peat and perlite, and MS medium), temperature conditions (14°C, 18°C, and 24°C) and photoperiodic regimes (12h/12h; 16h/8h). Different phythormone (naphthaleneacetic acid, NAA; 6-benzylamino purine, BA; and kinetin) concentrations were added in the MS medium for enhancing both germination and subsequent seedling propagation. Plants went through programming and forcing regimes to foresee (photoperiod of 18h light with fluorescent lamps of 600 lux and temperature of 17°-18°C) or delay (blue light and application of plant growth retardant) flowering. Cut flower vase life was evaluated by performing different preservative treatments (1-methylcyclopropene, 1-MCP; recut in tap water at 90 °C; and Chrysal Clear®). Ornamental characteristics of all Campanula species (wild and cultivated) were evaluated by a panel composed by 15 nurserymen. Overall, these experiments pointed at C. rapunculoides as the most promising native species. Therefore, its rooting capacity, attitude to be propagated by traditional vegetative propagation techniques and cultivation requirements are being evaluated.