A non-constitutive phenolic compound was isolated from date palm (Phoenix dactvlifera L.

Date palm (Phoenix dactylifera L.) is qualified as a 'tree' of great ecological and socio-economical importance in desert oases. Unfortunately, it is being decimated, especially in Morocco and Algeria, by a fusariosis wilt called bayoud and caused by Fusarium oxysporum f. sp. albedinis (Fao). Controlling this disease requires the implementation of an integrated management program. Breeding for resistance is one of the most promising component strategies of this program. Few naturally resistant cultivars with a mediocre fruit quality (dates) are known. Conventional and non-conventional methods are under development and have to use the simplest and easiest methods to screen for resistant individuals. The use of pathogen toxins as selective agents at the tissue culture step might be a source of variability that can lead to the selection of individuals with suitable levels of resistance to the toxin and/or to the pathogen among the genetic material available. Foa produces toxins such as fusaric, succinic, 3-phenyl lactic acids and their derivatives, marasmins and peptidic toxins. These toxins can be used bulked or separately as selective agents. The aim of this contribution was to give a brief overview on toxins and their use as a mean to select resistant lines and to initiate a discussion about the potential use of this approach for the date palm-Foa pathosystem. This review does not pretend to be comprehensive or exhaustive and was prepared mainly to highlight the potential use of Foa toxins for selecting date palm individuals with a suitable resistance level to bayoud using toxin-based selective media.

Phenolamides in the Rachis of Palms: Components of the Defence Reaction of the Date‐palm towards Fusarium oxysporum f.sp. albedinis, the Causal agent of ‘Bayoud’ This is the first study showing evidence of the production of phenolic and phenolamidic compounds in date palm tissues in response to attack by Fusarium oxysporum f.sp. albedinis (Foa), the causal agent of the wilt called bayoud. Marked quantitative and qualitative differences were recorded in the production of such compounds when infected and healthy rachis, were compared. In addition, localized accumulation of some compounds was detected when infected and healthy parts of the same rachis were analysed. Three induced hydroxycinnamoylamides were detected in high concentrations. They were isolated and tested for their toxicity against Foa. These compounds were shown to strongly inhibit conidial germination and germ tube growth of the pathogen and must be considered as phytoalexins. The role of amides in the date palm resistance to the bayoud is discussed.