Changes in the ultrastructure of the amphids of the potato cyst-nematode, Globodera-rostochiensis, during development and infection

The structure of the amphids of Globodera rostochiensis was examined at different stages of its life cycle. After hatching, the structure of the amphids does not change. The amphids of hatched second stage juveniles (J2), juveniles in the root and adult males appear similar in structure to each other and to those of other plant parasitic nematodes previously examined. However, in most unhatched J2 the structure of the amphid differs; the receptor cavity is devoid of secretory material and the sheath cell does not contain secretory granules seen in hatched juveniles and adults. The change from the apparently inactive state to that observed in the hatched J2 is not directly influenced by prior stimulation with potato root diffusate. There was no evidence that the feeding plug originated in the amphids.