Somatic embryogenesis in Norway Spruce (Picea abies (L.) Karst). Interactions between the gaseous environment and growth regulators

aba acide abscissique acide organique auxinas auxine auxins carbon dioxide cultivo de tejidos culture de tissu dioxyde de carbone embryon somatique espermidina espermina etefon ethephon ethylene etileno noruega norway organic acids oxygen picea abies picea rubens putrescina putrescine somatic embryos spermidine spermine tissue culture