Submitted to: International Symposium and Workshop on Desertification in Developed Countries
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 1994
Publication Date: N/A
Technical Abstract: Roots of common native grasses and shrubs growing in arid regions of the southwestern United States were analyzed for symbiotic fungi. In addition to classical interfaces formed by vesicular-arbuscular mycorrhizae, many other types of fungal interfaces were observed. Fungal isolates from roots of native plants formed associations typical of ectendo mycorrhizae with root organ cultures of alfalfa, blue grama, alkali sacaton and sideoats grama. Infected alfalfa roots accumulated high concentrations of phosphorus but prevented translocation to leaves and stem, while noninfected roots allowed a five-fold increase of phosphorus in plant tops, indicating that these fungi not only accumulate and store but regulate phosphorus transfer and possibly other essential nutrients and energy sources within the plant. Fungi associated with germinating seed of fourwing saltbush were also shown to degrade cellulose of the utricle and transfer carbon to the germinating seedling, which enhanced germination, vigor and establishment. A hypothesis was developed to explain how endophytic fungi affect survival of native plants and the nutrition of cultivated crops growing in arid regions. An understanding of how these fungi affect native plant communities would be valuable in the management of desert areas.