Giant cell formation was studied in the roots of potatoes grown in a soil infested with Heterodera rostochiensis.
Some indication of giant cell formation was found in roots fixed 14 days after planting of sprouted tubers in the infested soil.
Giant cells may be formed by the cells of the cortex, the endodermis, the pericycle and the parenchyma cells of the central vascular strand.
The first giant cells appear to be formed in the cortex and pericycle.
Giant cells in the cortex are only found near the head of an eelworm.
Giant cell formation by the parenchyma cells of the central vascular strand leads to no cambium and hence no secondary xylem being produced in those sectors of the root where they occur.
The occurrence of sectors of the root in which there is no secondary xylem gives the central vascular strand an irregular appearance.
Some giant cells may be multinucleate. They all have granular cytoplasm.