Biodiversity and specificity of fungal endophytes in semi-evergreen vine thickets (#164)
Endophytes are fungi that colonise plant tissues
without immediately causing disease. Endophytes are particularly abundant in
rainforests as these ecosystems have high rainfall and contain a diversity of
host plant species. Few studies have focussed on Australian rainforest
endophytes and much is to be learned regarding the fungal taxa present and the
basic ecology of their associations eg. specificity patterns. Semi evergreen
vine thickets are a type of dry rainforest principally occurring in inland
southern Queensland and northern NSW. These ecosystems are nationally
endangered and are threatened by expanding agriculture. Few ecological studies
exist on SEVT and the fungal endophytes of these ecosystems have not been described.
In a basic endophyte biodiversity study, leaves were sampled from each of 21 different
SEVT plant species at multiple sites in the Darling Downs region of south-east
Queensland. To assess fungal specificity
patterns, leaves were also sampled from 22 plants of the SEVT marker species, Geijera salicifolia, at 5 sites. Endophytes
were grown from leaf samples and were identified using molecular and
morphological methods. A total of 228 different fungal taxa were isolated from
the 21 different plant species in the biodiversity study, averaging 10
endophytes per plant (std=5.4). Common species included Nigrospora spp.,
Preussia spp., Pezizales spp., Cladosporium spp., Xylaria sp.
Epicoccum spp., Pestalotiopsis spp. and Phomopsis spp.
Many of these are cosmopolitan endophytes, with the exception of the Preussia
spp. and members of the Pezizales; the former which are more commonly known
as dung dwelling species and the latter not typically recorded as endophytes. Guignardia spp. were the most common
endophytes in G. salicifolia
constituting 49 out of the 188 fungi isolated.
These results suggest a level of fungal specificity in this host plant
species. The study has therefore
provided an overview of the fungal endophytes of a previously unexplored
Australian ecosystem and assessed some of the ecology of these associations.