Efficient regeneration of Eucalyptus urophylla from seedling-derived hypocotyls

Abstract

Seedling hypocotyls were used as explants to establish a regeneration protocol for Eucalyptus urophylla and N-phenyl-N′-[6-(2-chlorobenzothiazol)-yl] urea (PBU), one kind of di-substituted urea, was found useful growth regulator. The hypocotyls incubated on a modified Murashige and Skoog medium (SPCa), supplemented with 6.6 μM PBU and 0.57 μM indole-3-acetic acid (IAA) dedifferentiated and form calli (100% after 7 d). Compared with other growth regulator combinations, PBU stimulated more vigorous calli and restrained their darkening. In addition, the calli induced by PBU showed high frequency of adventitious buds formation (57%). Shoot proliferation and elongation was then stimulated on SPCa medium containing 0.44 μM 6-benzyladenine (BA), 0.54 μM naphthalene acetic acid (NAA) and 0.3 μM gibberellic acid (GA3). For rooting, shoots were cultivated on root induction medium containing 2.5 μM indole-3-butyric acid (IBA). Plantlets were then successfully transplanted to greenhouse. © Springer Science+Business Media B.V 2010.