Plant regeneration of the Australian native ornamental genus, Pandorea

Pandorea jasminoides and P. pandorana are successful Australian endemic ornamental species of the family Bignoniaceae. Vigorous growth and spectacular floral display make them popular landscape plants. Application of tissue culture could facilitate Pandorea breeding and improvement programmes, however, there is no report on in vitro regeneration of the genus Pandorea. A protocol for de novo shoot production is described for commercial cultivars of P. pandorana and P. jasminoides. Amenability of explants under in vitro conditions was found to differ between the two species. Direct shoot organogenesis of P. pandorana was obtained using node explants while seedling (epicotyl) explants of P. jasminoides were found to be responsive for shoot regeneration. A maximum of 13 and 15 shoots per explant of P. pandorana and P. asminoides, respectively, was obtained. Benzyladenine, BA, (8.8 µM) proved to be more effective for shoot regeneration than thidiazuron (TDZ) for P. pandorana while a combination of cytokinin (BA and -(choloro-4-pyridyl)-N-phynyl urea (CCPU) and auxin is required for P. jasminoides regeneration. However, no significant difference in rooting of in vitro regenerated P. pandorana and P. jasminoides shoots was observed. Regenerated shoots were rooted on a medium containing indolebutyric acid (IBA) and plantlets were successfully established under glasshouse conditions.