In vitro propagation of Vriesea reitzii, a native epiphyte bromeliad from the Atlantic rainforest

Resumo

The induction of nodular culture (NC) and the subsequent development of microshoots of V. reitzii are considered an in vitro propagation model-system with high regenerative performance. Current research analyzed the determinant factors of the in vitro morphogenesis control of bromeliads. Seeds excised from mature capsules were grown on medium MS basic (MSB), liquid or gelled, supplemented or not with α-naphthaleneacetic acid (NAA), 6-benzilaminopurine (BAP) or thidiazuron (TDZ). The regeneration and elongation of microshoots were evaluated from NC sub-cultivated on MSB medium on liquid culture medium supplemented with different concentrations of indolyl-3-acetic acid (IAA) and gibberellic acid (GA₃). Plant growth regulators (PGR) supplemented into the medium MSB inhibited the germination of the seeds and induced NC in the second week of growth. The induced NC on MSB medium with NAA (4 µM) and sub-cultivated on MSB medium with NAA (2 µM) plus N⁶(2-isopentenyl) adenine (2-iP) (2 µM) showed granular texture and high rate of proliferation. NC sub-culture in MSB medium with IAA (4 µM) provided a higher average number of microshoots (1,478 shoots g^-1 of NC). Shoots over 3.0 cm resulted in more than 95% ex vitro survival.