Réaction phénolique de quatre clones de palmier à huile inoculés par Fusarium oxysporum f. sp. elaeidis

En Afrique, la culture du palmier a huile est menacee par la fusariose causee par Fusarium oxysporum  f. sp. elaeidis (F.o.e). Chez cette plante, l’activite antifongique des phytoalexines a ete demontree dans la lutte contre ce champignon au cours des premieres semaines apres inoculation. L’objectif de cette etude est de selectionner des clones de palmier a huile resistants a F.o.e. sur la base de leur synthese phenolique. Pour ce faire, les racines blessees des plantules ont ete inoculees par F.o.e et les non inocules ont servi de temoin. Les racines ont ete prelevees a differents temps. Les extraits racinaires des plantules ont ete doses par le reactif Folin Ciocalteu pour quantifier les phenols totaux des plants inocules (IT) et non inocules (NI). Les resultats ont montre que les clones resistants ont reagi a l’infection des le premier jour apres inoculation. Par contre, les clones sensibles ont reagi le cinquieme jour. Au huitieme jour, la quantite de phenols baisse considerablement chez les clones sensibles et augmente ou se stabilise chez les clones resistants. Ce resultat pourrait servir pour la selection des clones resistants a F.o.e avant la mise au point des marqueurs phenoliques de tolerance du palmier a huile a ce pathogene. © 2016 International Formulae Group. All rights reserved. Mots cles: Clone, sensible, resistant, Fusarium oxysporum f. sp. elaeidis , Palmier a huile, phenols English Title: Phenolic reaction of four clones of oil palm inoculated by  Fusarium oxysporum f. sp. elaeidis English Abstract In Africa, the cultivation of oil palm is threatened by Fusarium oxysporum f. sp. elaeidis which is responsible of the fusarium. The antifungal activity of phytoalexins was demonstrated in the fight against this fungus in the first weeks after inoculation of the oil palm plant. However, the phenolic behavior of sensitive and tolerant clones over time remains unclear. The objective of this study is to select resistant oil palm clones F.o.e. on the basis of their phenolic synthesis. In order to achieve this aim, the roots of the oil palm plants were injured and inoculated with F.o.e. The uninoculated oil palm plants were used as the control. The roots were collected at different times. The root extracts of the oil palm plants were measured using the Folin Ciocalteu reagent in order to quantify the total phenols present in both the inoculated (IT) and the non-inoculated (NI) plants. The results showed that the tolerant clones reacted to infection from the first day after inoculation. On the other hand, the sensitive clones reacted the fifth day. On the eighth day, the amount of phenols was found to be significantly lower in the susceptible clones. In contrast, the amount of phenols was found to be higher or stable in the resistant clones. This result could be used to select the resistant clones to F.o.e before the development of phenolic markers for oil palm plant infections. © 2016 International Formulae Group. All rights reserved. Keywords: Clone, susceptible, resistant, Fusarium oxysporum f. sp. elaeidis , oil palm, phenols