Isolation of a natural hatching stimulus, glycinoeclepin A, for the soybean cyst nematode

Abstract

The cyst nematodes (genera Heterodera, Globodera and others)¹ generally have a limited host range. This specificity arises from the fact that the hatching of larvae from cysts occurs in response to specific stimuli secreted by the host plants^2–4. Because of the scientific interest and importance in agriculture of these stimuli, since their first recognition⁵ in 1922 much time and effort^2–4 has been expended in attempts to purify and characterize them. However, success has been limited by the extremely small amounts of active substance available. We report here the isolation of a natural hatching stimulus for the soybean cyst nematode from the roots of kidney bean. The substance, designated as glycinoeclepin A, stimulates the hatching of larvae from the eggs in vitro at a concentration of 10⁻¹¹ to ∼10⁻¹² g ml⁻¹ in water at 25 °C.