SURVIVAL AND SPREAD OF THE ENDOPHYTE STAGONOSPORA-PTERIDIICOLA IN PTERIDIUM-AQUILINUM, OTHER FERNS AND SOME FLOWERING PLANTS

Pteridium aquilinum (L.) Kuhn was sampled for colonization by Stagonos pora pteridiicola in Great Britain, Hungary and Australia. British sam ples gave the highest incidence of 68 % during September and 12 % at t he beginning of the growing season. Hungarian samples showed a similar frequency. The fungus was not found in Australian bracken. Five field -collected fern species other than bracken did not contain the fungus in May when bracken already had a colonization frequency of 12 % in th e pinnules. Sampling after the bracken had died in November demonstrat ed that the fungus had continued growth as a saprobe. Glasshouse-groan bracken sprayed with a spore suspension showed 96 % colonization afte r 21 d, whereas four fern species and five flowering plants, similarly treated, gave colonization frequencies of 0-3 %. Other glasshouse-gro wn bracken, similarly sprayed, showed that colonization declined over 5 months from 75 % to 40 % and that the fungus showed little spread in to fresh unsprayed growth on these plants. The possible species specif icity of the fungus is discussed.