Effects of Variation in Water Potential on the Viability and Behaviour of Conidia of Peronospora Tabacina Adam

Abstract

A method is described for the collection of dry conidia of P. tabacina. Conidia were shown to lose or gain water according to the ambient humidity. When stored at 91'4% R.H., 50% of conidia were swollen, while all were shrunken at 88% RH. and all swollen at 94% RH. Average weight per conidium increased from 1· 04 ng at 0% R.H. to 2· 65 ng at 99% R.H.