Histological Alterations Induced by Rotylenchulus reniformis Alone or Simultaneously with Meloidogyne incognita on Banana Roots

Abstract

A histopathological investigation of Rotylenchulus reniformis Linford and Oliveira on banana (Musa acuminata L.) roots showed that the nematode penetrates the cortex perpendicular to the stele, and establishes a permanent feeding site in the endodermis. Nematode feeding induced the fusion of endodermal, pericyclic, and vascular parenchymal cells to form a syncytium with hypertrophied nuclei and prominent nucleoli. Females of R. reniformis were also observed in a semiendoparasitic feeding position on galls induced by Meloidogyne incognita (Kofoid and White) Chitwood. Sections of banana roots infected concomitantly with the two nematode species showed R. reniformis syncytia formed by endodermal and pericyclic cells at the periphery of the stele, and M. incognita giant cells derived by vascular parenchyma or differentiating vascular cells in the central part of the stele.