Perez Nunez M.T. auteur aut IRD Chan J.L. auteur aut IRD Saenz L. auteur aut IRD Gonzalez T. auteur aut IRD Verdeil Jean-Luc auteur aut IRD Oropeza C. auteur aut IRD text journalArticle eng text/pdf born digital access Coconut is one of the most recalcitrant species to regenerate in vitro. Although previous research efforts using plumule explants have resulted in reproducible somatic embryogenesis, efficiency is only 4 or 10 somatic embryos per plumule without or with a brassinolide treatment, respectively. In order to increase the efficiency of somatic embryogenesis in coconut, two different approaches were evaluated and reported here: secondary somatic embryogenesis and multiplication of embryogenic callus. Primary somatic embryos obtained from plumule explants were used as explants and formed both embryogenic callus and secondary somatic embryos. The embryogenic calluses obtained after three multiplication cycles were capable of producing somatic embryos. The efficiency of the system was evaluated in a stepwise process beginning with an initial step for inducing primary somatic embryogenesis followed by three steps for inducing secondary somatic embryogenesis followed by three steps for embryogenic callus multiplication, and finally production of somatic embryos from callus. The total calculated yield from one plumule was 98 000 somatic embryos. Comparing this to the yield obtained from primary somatic embryogenesis results in about a 50 000-fold increase. When compared to the yield previously reported in the literature with the use of a brassinolide treatment, it is about a 10 000-fold increase in yield. The present protocol represents important progress in improvement in the efficiency of coconut somatic embryo production. specialized coconut secondary somatic embryogenesis callus multiplication 076 42 1 37-43 2006 https://www.documentation.ird.fr/hor/fdi:010052300 10.1079/IVP2005722 [F B010052300] https://www.documentation.ird.fr/hor/fdi:010052300 https://www.documentation.ird.fr/intranet/publi/depot/2011-07-27/010052300.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2006-03-30 2017-08-23 fdi:010052300 fre