A Simple and Rapid Method for Micropropagation of Petunia × hybrida F1 ‘Opera Supreme Pink Morn’

For efficient regeneration of Petunia × hybrida F1 'Opera Supreme Pink Morn', a simple in vitro micropropagation protocol was developed. Axillary bud explants dissected from 30-day-old in vitro-grown seedlings sprouted from hybrid seeds were cultured on Murashige and Skoog (MS) medium supplemented with 36 combinations of 6-benzylaminopurine (BA; 0.00, 0.50, 1.00, 2.00, 3.00 and 5.00 mg l-1) and α-naphthaleneacetic acid (NAA; 0.00, 0.10, 0.50, 1.00, 1.50 and 3.00 mg l-1). The BA alone at 0.50 or 2.00 mg l-1 was found to be best for shoot length, shoot number, node number, and leaf number than other concentrations of BA and BA in combination with NAA. The highest number of shoots (8.44) and the maximum average shoot length (13.16 cm) were recorded on MS medium supplemented with 0.50 mg l-1 BA without NAA. Root length (5.20 cm) and root number (8.77) were the maximum in the medium containing 0.10 mg l-1 NAA. The plantlets regenerated in vitro with well-developed shoots and roots were successfully established in pots containing peat and perlite and grown in a greenhouse within 4 weeks with a 100% survival rate. The regenerated plants were morphologically identical with donor plants and did not show any detectable phenotypic variation. Overall, BA at 0.50 or 2.00 mg l-1 had a better effect on shoot system than other concentrations of BA and BA in combination with NAA. NAA induced more root formation and root growth than BA.