Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2013

Biodiversity and specificity of fungal endophytes in semi-evergreen vine thickets (#164)

John Dearnaley 1 , Rachel Mapperson 1
  1. Australian Centre for Sustainable Catchments, University of Southern Queensland, Toowoomba, QLD, Australia
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.