Investigations into the biochemical basis for nematode resistance in rootsof three Musa cultivars in response to Radopholus similis infection

The Musa cultivars, Dwarf Cavendish, Yangambi Km5 and Kunnan, exhibit consi derable differences in resistance to Radopholus similis. Infection resulted in significant increases in condensed tannins and flavan-3,4-diols in root s (P < 0.001). The highly resistant cultivar Kunnan had the highest levels of condensed tannins before and after infection. The preinfection levels we re similar to the postinfection levels of the two other cultivars. Tannins had mostly procyanidin character, but Kunnan also contained propelargonidin s; these compounds may be involved in the resistance mechanism. It is sugge sted that the butanol/HCl assay be used as a rapid test in screening for re sistance to R. similis.