HISTOPATHOLOGY OF BROAD BEAN ROOTS INFECTED BY THE LESION NEMATODE PRATYLENCHUS PENETRANS
AbstractThe histological changes induced by Pratylenchus penetrans in broad bean (Vicia faba L.) roots were studied and described. Histology of infected roots during early and later stages of infections showed the nematode located entirely within the cortex and generally oriented longitudinally to the vascular cylinder. All stages in the life cycle of the nematode were observed in infected roots. Nematodes moved intracellularly causing extensive rupturing of cell walls, cavities and thickening of cell walls or necrosis of cells around feeding sites. There was no hypertrophy of cortical cells associated with invasion of P. penetrans but thickening of cell walls of 2-3 layers of cell adjacent to the nematode were observed. Several cells showed granular cytoplasm and hypertrophied nuclei as a typical reaction to feeding. Stelar tissues were unaffected by feeding and damage to the epidermis was characterized by necrotic areas 10-60 mm long.