“…Plants in this stage are then ready for acclimatization (Pires et al, 2003;Figure 2a As reported above, somatic embryogenesis is a regeneration strategy with enormous potential for breeding programs. Somatic embryos were developed in Q. canariensis (Bueno et al, 1996;, Q. rubra (Vengadesan & Pijut, 2009), Q. serrata Takur et al, 1999), Q. robur (Cuenca et al, 1998;Endemann et al, 2002;Wilhelm et al, 1999), Q. acutissima (e.g., Kim, 2000) and Q. petrea (Chalupa, 2005). However, not only most studies use juvenile sources of explants (e.g., zygotic embryos and seedlings), but also plant conversion frequencies are still low, supporting the recalcitrance of these species.…”