Abstract:
Fusarium agapanthi is newly reported from the centre of origin of Agapanthus in South Africa, where it is
associated with dead flower stalks of Agapanthus praecox. Mjuua agapanthi, a rare hyphomycete with a morphology
corresponding to asexual morphs of Pyxidiophora, was isolated as mycoparasitic on F. agapanthi, along with bacteria
that co-occurred in synnematal heads of M. agapanthi. Germinating conidia of M. agapanthi were observed to parasitise
germinating conidia of F. agapanthi. Although M. agapanthi could not be cultivated on its own, the association with
Fusarium proved to not be restricted to F. agapanthi, as it could also be cultivated with other Fusarium spp. Mjuua
agapanthi is a member of Pyxidiophorales, an order of obligate insect parasitic microfungi. The exact role of the bacteria in
synnematal heads of M. agapanthi remains to be further elucidated, although one bacterium, Alsobacter metallidurans,
appeared to cause lysis of the synnematal conidial cell walls. This discovery suggests that many unculturable obligate
biotrophic microbes can probably be cultivated if co-cultivated with their respective hosts.
