Phenolics Involvement In Sweet Potato Resistance-Meloidogyne Incognita And M. Javanica

Ruben  M. Gapasin,; Evelyn Mae  T. Mendoza,; Rodrigo  B. Valdez,

Phenolics Involvement In Sweet Potato Resistance-Meloidogyne Incognita And M. Javanica

Ruben M. Gapasin | Rodrigo B. Valdez | 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 cu ltivars even as low as 10% concentration. The com-pounds 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 infec-tion as indicated by the stronger color intensity of the fluorescent spots.

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