Effects of autoinhibition on hyphal growth in Coprinus disseminatus

Abstract

Colonies of Coprinus disseminatus growing in agar reduced the extension rate of surface colonies which were separated from them by ‘Cellophane’. Inhibition of surface colony extension was detectable when the margin was close behind that of the submerged colony and reached a maximum over parts of the submerged mycelium which were between 1 and 4 days old. The extension rate of the surface mycelium was at least partially restored by removal of agar containing submerged mycelium from beneath the growing margin of the surface colony. This autoinhibition reduced the extension rate and tip diameter of main hyphae and young primary branches. Within most treatments involving different levels of autoinhibition there was a significant linear regression between extension rate and hyphal diameter for main and primary branch hyphae separately. Between treatments there was significant heterogeneity in the slopes of these regression lines. Within treatments the slopes of the regression lines for main and branch hyphae were similar but branch hyphae extended more slowly than equally wide main hyphae.