Ultrastructural Response of Coffee Roots to Root-Knot Nematodes, Meloidogyne Exigua and M. Megadora


  • A. Cristina F. de O. Rodrigues
  • Isabel M. de O. Abrantes
  • Maria Teresa Melillo
  • Teresa Bleve-Zacheo


coffee, host-parasite interactions, hypersensitivity, resistance, root-knot nematodes, sus-ceptibility, TEM, ultrastructure


Rodrigues, A. C. F. de O., I. M. de O. Abrantes, M. T. Melillo, and T. Bleve-Zacheo. 2000. Ultrastructural response of coffee roots to root-knot nematodes, Meloidogyne exigua and M. megadora . Nematropica 30:201-210. Histological and ultrastructural changes induced in Coffea arabica cv. Catuaiamarelo and Catimor ( Coffea arabica cv. Caturra þ Timor Hybrid) by two populations of Meloidogyne exigua and one of M. megadora are reported. All second-stage juveniles of both species penetrated through the rhizodermis of the root directly behind the root cap and reached the stele near the vascular elements. In Catuaiamarelo roots, cells acting as feeding sites increased their synthetic activity and became multinucleate cells. Nuclear activity and dense cytoplasm observed in cells of roots inoculated with M. exigua indicated a susceptible response of the coffee plants. Seedling cells fed upon by M. megadora showed retraction and roughening of the inner wall surface, great presence of param