Résumé
Various problems are encountered in the establishment and maintenance of embryogenic cultures. The production of embryogenic material is often a difficult and lengthy process, as observed notably with oilpalm and coconut (Duval et al. 1995; Verdeil and Buffard-Morel 1995). The progressive decrease of embryogenic potential over time is a phenomenon which is commonly observed with embryogenic cultures (Withers 1985). Moreover, risks of somaclonal variation increase in line with the extension of the culture period (Reisch 1984). Finally, it is difficult and costly to maintain large numbers of proliferating cultures in large-scale production laboratories. Tools which would allow to overcome these difficulties are urgently needed to enhance the applicability of somatic embryogenesis processes for the mass propagation of elite material.