Changes in the Structure of Amphidial Exudate and the Nature of Lectin Labelling On Freshly Hatched, Invaded and Emigrant Second Stage Juveniles of Globodera Rostochiensis

Although four lectins bind to the amphidial exudate of freshly hatched juveniles of potato cyst nematode, only concanavalin A adheres to the lip region. The mannosyl/glucosyl residues recognised by concanavalin A may originate from either the amphids, inner labial receptors or stylet. Juvenile nematodes which migrated from the roots of resistant or susceptible potatoes differed in their lectin-binding pattern from freshly hatched nematodes. Many emigrants labelled extensively on the front third of the body with agglutinins of soya bean and wheat germ as well as concanavalin A. Dolichos biflorus agglutinin did not label any of the emigrants. Some individuals were also completely unlabelled by any of the lectins. The structure of amphidial exudate changed from reticulate in freshly hatched juveniles to fibrillar in sedentary second stage juveniles and emigrants.