Histological, histochemical and phytochemical characterization of #Coffea# spp. resistance to the root-knot nematode #Mmeloidogyne paranaensis#

Meloidogyne paranaensis is a root-knot nematode (RKN) affecting coffee production in Latin America. Simultaneous histological and histochemical studies were carried out on Coffea arabica cv Caturra (susceptible), a wild Ethiopian accession of Coffea arabica (resistant ) and a rootstock Coffea canephora cv Nemaya (resistant) after inoculation with this RKN in order to characterize compounds accumulating after infection in resistant cultivars. No hypersensitive-like reaction was induced neither in C. arabica, nor in C. canephora resistant genotypes. Instead, these two resistant coffee genotypes develop the same original resistance mechanisms against M. paranaensis i.e. flavonoids accumulation into giant cells of the feeding sites induced by the RKN. Chlorogenic acids accumulating around infestation sites could act as flavonoid precursors. (Resume d'auteur)