A MODEL SYSTEM FOR RAPID SELECTION FOR RESISTANCE AND INVESTIGATION OF RESISTANCE MECHANISMS IN FUSARIUM-WILT OF OIL PALM

Fusarium wilt (Fusarium oxysporum f.sp elaeidis) is the most serious d isease of oh palm in Africa. Control measures are dependent upon breed ing for resistance, but the lack of a rapid screen for resistance and lack of understanding of the underlying resistance mechanisms has cons trained breeding programmes. A novel petiole infusion technique is rep orted that exploits the ability of the majority of petiole cells to ex press disease resistance or susceptibility. A clear correlation was fo und between disease resistance or susceptibility of six clones and ext ernal symptoms and fungal colonization in petioles. Antifungal compoun ds accumulated in resistant but not in susceptible clones in response to inoculation; there was also some evidence of preformed antifungal c ompounds in resistant clones. Further investigation of resistance mech anisms can be undertaken using this model system. The use of this nove l technique, both as a potential rapid replacement for current nursery selection methods (time reduced from 8 months to 8 days) and as an as sessment of resistance in individual held palms, is discussed.