Cabasan M. T. N. auteur aut IRD Kumar A. auteur aut IRD Bellafiore Stéphane auteur aut IRD De Waele D. auteur aut IRD text journalArticle eng text/pdf born digital access The root-knot nematode, Meloidogyne graminicola, can cause substantial rice yield losses. Understanding the mechanisms of resistance to this nematode species in known resistant rice genotypes may help to improve rice genotypes, aiming at developing and implementing environment-friendly and cost-effective nematode management strategies. Using susceptible and resistant rice genotypes, a comparative analysis of histological response mechanisms was made during two phases of the nematode colonisation: i) root penetration; and ii) subsequent establishment and development by M. graminicola second-stage juveniles (J2). Two types of defence response mechanisms could be distinguished in the resistant rice genotypes. The early defence response consisted of a hypersensitive response (HR)-like reaction in the early stage of infection characterised by necrosis of cells directly affected by nematode feeding. This HR-like reaction was observed only in the M. graminicola-resistant Oryza glaberrima genotypes and not in the M. graminicola-susceptible O. sativa genotypes. The late defence response took place after the induction of giant cells by the J2. Giant cells usually collapsed and degenerated before J2 developed into adults. Structural features of the roots of the susceptible O. sativa showed greater root and stele diam. and cortex thickness than the resistant O. glaberrima genotypes. Desired features of plants with resistance to M. graminicola elucidated in this study can be used for selection of plants for breeding programmes. specialized giant cells hypersensitive response-like reaction penetration resistance root morphology susceptibility PHILIPPINES 076 074 16 1 73-81 2014 1388-5545 https://www.documentation.ird.fr/hor/fdi:010061721 10.1163/15685411-00002746 1388-5545 [F B010061721] https://www.documentation.ird.fr/hor/fdi:010061721 https://www.documentation.ird.fr/intranet/publi/2014/02/010061721.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2014-03-03 2017-08-23 fdi:010061721 fre