A Simple Technique for Time-Lapse Photomicrography of Microfungi in Plate Culture

Abstract

Developmental characters have recently gained the ascendancy in hyphomycete taxonomy, and this laboratory has undertaken detailed analyses of the diverse methods of conidiophore and conidium ontogeny exhibited by these fungi. Cole and Kendrick (1968a) described an ultra-thin culture chamber which has subsequently been used with considerable success in time-lapse photomicrographic studies (Kendrick, Cole and Bhatt, 1968; Kendrick and Cole, 1968, 1969; Cole and Kendrick, 1968b, 1969). Unfortunately, some hyphomycetes do not lend themselves to this technique. Three problems have been encountered. (i) Sporogenous cells which normally produced long chains of conidia in plate culture would form only one or a few spores in the culture chamber before succumbing [e.g., Scopulariopsis brevicaulis (Sacc.) Bainier, and Deightoniella torulosa (Syd.) M. B. Ellis]. (ii) Profuse vegetative mycelium developed before sporulation began, thus obscuring the subsequent events of conidium ontogeny [e.g., Arthrinium phaeospermum (Corda) M. B. Ellis]. (iii) In some fungi which normally produced two kinds of spores sequentially, only the first developed; or, if the second did form, previously differentiated elements hid its ontogeny from the camera [e.g., chlamydospores of Thielaviopsis paradoxa (de Seynes) Hohnel were obscured by earlier formed phialides and phialospores, while those of T. basicola (Berk. and Br.) Ferr. failed to develop]. These problems necessitated an exploration of alternative techniques. Since those fungi which did not adapt well to the culture