OCCURRENCE OF VESICULAR MYCORRHIZAL FUNGI IN DRYLAND SPECIES OF RESTIONACEAE AND CYPERACEAE FROM SOUTH-WEST WESTERN-AUSTRALIA

Species of Cyperaceae and Restionaceae were examined for presence of v esicular-arbuscular (VA) mycorrhizal fungi in natural habitat in south -west Western Australia. VA mycorrhizal fungi were detected in roots o f two species of Cyperaceae (Lepidosperma gracile and Tetraria capilla ris), and two species of Restionaceae (Alexgeorgea nitens and Lyginia barbata), all representing the first records for these genera. Results indicated a very short seasonal period of infection, with VA mycorrhi zal fungi representing the genera Acaulospora, Glomus, Scutellospora a nd Gigaspora identified in roots. VA mycorrhizal fungi were prominent from late autumn to early winter (April-June) and in up to 30% of the young, new season's roots as they penetrated the upper 10 cm region of the soil profile. Mycorrhizal infection was not evident during the dr y summer months. This study suggests that mycorrhizas may be important for nutrition of these hosts in these environments but their activity is restricted to a brief period of the growing season.