The Changes in Cyst Form during the Development of the Cyst of Heterodera rostochiensis and H. schachtii

Abstract

The difference in the final shape of the cyst of H. rostochiensis and H. schachtii is shown to be due to patterns of growth during cyst development. The greatest change of form takes place during the first 6 days for H. rostochiensis and the first 12 days for H. schachtii. The principal difference between the cyst shape in the two species is due to the greater increase in length in relation to breadth of the growing H. schachtii cyst. Premature tanning, due to environmental factors, is shown to affect final cyst form.