Relationship between juvenile hatching and acridine orange fluorescence of Heterodera glycines eggs

Uptake of acridine orange resulting from increased eggshell permeability is a reliable predictor of hatching for Globodera rostochiensis eggs. We conducted laboratory experiments to determine whether fluorescence of Heterodera glycines eggs stained with acridine orange correlated with hatching. Heterodera glycines eggs were incubated in sterile distilled water, zinc sulphate or soybean root diffusate and were stained with acridine orange 24 h prior to assessing fluorescence. Fluorescence of mature eggs positively correlated with hatching in zinc sulphate. Correlations in soybean root diffusate were positive, negative or non-existent, depending on the concentration of the diffusate. Although there were some significant correlations between hatching and fluorescence of H. glycines eggs in zinc sulphate, the relationships were not sufficiently consistent for this technique to be used reliably to predict H. glycines hatching in soybean root diffusate.