Résumé
The mantled floral phenotype which occurs in somatic embryo-derived oil palms (Elaeis guineensis Jacq.) shows detrimental consequences on the large scale production of clonal planting material for this strategic oil crop. Indeed, mantled somaclonal variants display a feminization of male floral organs which bears a major threat on the formation of oil-producing fruits. The unpredictability of such variation warrants the search for molecular markers for an early detection. In parallel, the mantled phenotype provides a challenging puzzle to the researcher since it is both reminiscent of floral abnormalities governed by MADS Box genes in model plants and susceptible to provide insights into the particulars of sex differentiation and flower organogenesis in Palms species. Since a genome-wide deficit in DNA methylation has been demonstrated in mantled tissues and since gene expression differs substantially with respect to true-to-type material, it is now widely accepted that this unstable variant phenotype is correlated with (and likely caused by) the disturbance of epigenetic mechanisms during the in vitro micropropagation process, which involves a series of differentiation/dedifferentiation phases. Our talk provides an update on ongoing research work aimed at deciphering the role of epigenetic regulations in the floral development of the oil palm. (Texte integral)