Mycogeography of Fusarium: Fusarium Species in Soils From Palm Valley, Central Australia.

Abstract

The identity and abundance of Fusarium species in soils from Palm Valley in the central arid ranges of Australia were assessed in two successive years. This location enabled a comparison of Fusarium species in soils from within the valley where soil moisture is more readily available and the dominant plants are shallow rooted palms, with Fusarium species in soils from the arid rim characterised by spinifex grasses and xeric shrubs. Sixteen sites were sampled. Of the sites within the valley, four were dominated by palms, three by cycads, and four by endemic grasses. The five arid habitats sampled from the rim were dominated by grasses. Twelve Fusarium species and one subspecies were isolated using the dilution plate technique and peptone-PCNB agar. Fusarium oxysporum was recovered from all sites in both years irrespective of vegetation or moisture availability. Fusarium compactum, F. solani and F. scirpi were recovered from most sites. The greatest range of species was recovered from grassed sites, with fewest species being recovered from cycad sites. Taxonomic characteristics of the isolates of F. polyphialidicum are described in detail because they expand the boundaries of the published description.