A aclimatização é a fase mais crÃtica da micropropagação em razão de vários fatores que podem impactar
a sobrevivência das plantas. O objetivo deste trabalho foi estabelecer um protocolo de pré-aclimatização
seguido de aclimatização em hidroponia para plantas micropropagadas de Eucalyptus saligna. A pré-aclimatização
consistiu nos tratamentos: 1) controle (frascos cobertos com tampas de polipropileno rÃgido);
2) frascos cobertos com filme de PVC contendo 10 furos (4 mm²/furo); e 3) frascos de cultura totalmente
descobertos. Foram adicionados 10 mL de água destilada e autoclavada nos frascos dos tratamentos 2 e 3.
Após 72h as plantas foram cultivadas em areia grossa em bandeja de polietileno expandido, que flutuava
sobre a solução nutritiva constituÃda do meio de cultura MS modificado lÃquido (sais com ½ e FeEDTA com
¼ da concentração original e sem os constituintes orgânicos) dentro de uma bacia de plástico. As bacias do
cultivo hidropônico permaneceram em sala de crescimento por cinco dias e em seguida foram transferidas
para a casa de vegetação. O cultivo hidropônico teve duração de 14 dias e as plantas foram então transferidas
para substrato Plantmax
Acclimatization is the most difficult stage of the micropropagation process due to several factors that can affect
plant survival. The aim of this work was to develop a protocol for acclimatization of Eucalyptus saligna in hydroponics
following a pre-acclimatization stage. The pre-acclimatization consisted of the treatments: 1) control
(flasks covered with rigid polypropylene caps); 2) flasks covered with PVC film perforated with 10 holes
(4 mm²/hole); and 3) uncapped culture flasks. Ten mL of distilled autoclaved water were added into the flasks
of treatments 2 and 3. After 72 hours, plants were cultivated in thick sand in an expanded polyethylene tray
floating on a nutritive solution consisting of modified liquid MS medium (salts and FeEDTA with one-half and
one-quarter of the original concentration, respectively, and without organic constituents) inside a plastic
tray. Trays containing the hydroponic culture were placed in a growth room for 5 days and then transferred to
a greenhouse. Hydroponic culture lasted 14 days, then the plants were transferred to Plantmaxâ„¢ HT substrate.
At the end of the hydroponic cultivation the survival rate of the plants under treatment 3 reached 90%, which
was significantly higher than the rates observed for treatments 1 and 2, with 40% and 60%, respectively. After
14 days of culture in Plantmaxâ„¢ HT substrate, there was no variation in plant survival. Pre-acclimatization
in uncapped flasks followed by 14 days of hydroponic cultivation allows an efficient acclimatization of micropropagated
plants of E. saligna.
