Arbuscular mycorrhizal associations in the southern Simpson Desert

The plants of the Simpson Desert are adapted to one of the driest regions o n the Australian continent and grow in generally nutrient-poor soils. Surve ys were conducted at three sites in the southern Simpson Desert to determin e the arbuscular mycorrhizal (AM) status of 52 species from 28 families of annual and perennial plants. Roots from all plants were examined for the pr esence of internal and external hyphae, vesicles, arbuscules and coils to d etermine presence and extent of mycorrhizal colonisation. Of the plant spec ies surveyed, 38 (73%) had formed mycorrhizal associations. The AM status o f 47 species is reported for the first time, including of members of the Fr ankeniaceae and Myoporaceae families. No correlations were found between si te (dune or interdune) or life form and the number of species forming AM as sociations. Two species in the normally non-mycorrhizal Chenopodiaceae, Sal sola kali L. and Sclerolaena diacantha (Nees.) Benth. had mycorrhiza. Arbus cules and/or vesicles were observed in the roots of all mycorrhizal plants except three species, Solanum ellipticum R.Br., Gnephosis eriocarpa (F. Mue ll.) Benth. and Eremophila longifolia (R.Br.) F. Muell., in which only coil s of hyphae were observed.