Growth and photosynthetic responses during ex vitro acclimatization of Etlingera Elatior (Jack) rm smith (torch ginger)

Crescimento e respostas fotossintéticas durante aclimatização ex vitro de Bastão-do-imperador (Etlingera elatior Jack RM Smith)

ABSTRACT

Torch ginger (Etlingera elatior (Jack) RM Smith) can be propagated in vitro, but there is currently little information about the stages of acclimatization and adaptation for torch ginger in a greenhouse. The objective was to study the growth responses, survival and photosynthetic response during the acclimatization of plants maintained on three different substrates (Plantmax forestry^(r), sand and 1:1 Plantmax forestry^(r) and sand) under three shading conditions (50% red and blue shading nets and control without shading nets). The highest leaf and shoot numbers per plant and survival rate were observed in treatments with the Plantmax forestry^(r) type substrate in the absence of shading. In vitro culture plants behaved similarly or better than rhizome propagated control plants with regard to the net photosynthesis rate, carboxylation efficiency, stomatal conductance and transpiration rate. In general, for both conditions, in vitro and control plants had similar efficiency of biochemical functions and of photosystem II. These results show that plants derived from in vitro culture exhibit satisfactory physiological yield and greenhouse acclimation capacity.

Keywords
torch ginger; growth curve; gas exchange; photoautotrophy