In vitro regeneration of Centaurium erythraea Rafn from shoot tips and other seedling explants

Various explants from 30-day-old seedlings of Centaurium erythraea Rafn were evaluated for their morphogenetic capacity under in vitro culture conditions. Shoot formation from shoot tip explants was achieved mainly through adventitious bud differentiation. The highest number of shoots (up to 43.3 ± 2.2 from a single shoot tip) was obtained on Murashige and Skoog medium (MS) supplemented with indole-3-acetic acid (IAA) (0.57 μM) and 6-benzylaminopurine (BAP) (4.4 μM). Adventitious shoot regeneration was also achieved through organogenesis from calluses obtained from hypocotyls, cotyledons, roots and leaves on MS medium containing IAA (2.85 μM) and BAP (0.88 μM). Significant differences were noted between explant types in their effects on shoot regeneration. In the primary culture, the best response was obtained either from calluses derived from roots or leaves (44.4 ± 4.5 and 40.2 ± 6.0 shoots per callus, respectively). The number of subcultures of inoculated calluses affected both the multiplication rate (the number of shoots/explant) and shoot morphology (the frequency of shoot hyperhydricity). Shoots rooted with the frequency of 94-100% after culture on MS medium without growth regulators. Plantlets were successfully acclimatized (97%) under high relative humidity and then moved to the greenhouse.