Ruben M. Gapasin, Rodrigo B. Valdez and Evelyn Mae T. Mendoza
ABSTRACT
The possible involvement of phenols in sweet potato resistance to root-knot nematode was shown by the reduced number of eggs hatched and high larval mortality of Meloidogyne incognita and M. javanica exposed to root extracts of the resistant cultivars even as low as 10% concentration. The compounds present in the extracts were heat resistant, of low molecular weight and water soluble.
Thin layer chromatography (TLC) revealed two distinct groups of blue fluorescent spots in susceptible and resistant sweet potato extracts with Rf values corresponding to chlorogenic acid, scopoletin and esculin. More phenolics accumulated in root extracts of resistant sweet potato cultivars following infection as indicated by the stronger color intensity of the fluorescent spots.
Keywords: Sweet potato. Meloidogyne incognita. M. javanica. Thin layer chromatography (TLC). Chlorogenic acid. Scopoletin. Esculin. Phenolics.
Annals of Tropical Research 10(2):(1988)
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