The ISCB project:
(Fritz Oehl, Kurt Ineichen, Florian Walder, Jürg Schulze, Dirk Redecker, Mathimaran Natarajan)
In this project, we are studying the diversity of arbuscular mycorrhizal fungi (AMF) in soils from a broad spectrum of agricultural systems and from undisturbed seminatural grasslands. Our agricultural field sites are widely differing in input intensity. For instance, there are maize monocultures and several types of organic management. All our sites are in the local area around Basel, known as the "three country corner" (Switzerland/Germany/France). Most of them are on Loess soils and therefore easily comparable.
We closely collaborate with Dr. Paul Mäder at the Swiss Federal Institute for Organic Agriculture (FIBL), where we study AMF in the unique DOK trial. In this long term experiment, soils have been cultivated according to two different organic farming systems (Biodynamic, Organic) and conventional methods since 1978.
Within the framework of the "Indo-Swiss Cooperation in Biotechnology" project we collaborate with partner institutions in India (TATA Energy Research Institute, New Delhi; Patnagar University of Technology, Patnagar) and Switzerland (Laboratory of Microbiology at the University of Neuchâtel). Our colleagues in India are characterizing their local AMF communities in parallel to our efforts in Europe. There is a frequent exchange of materials and expertise with the Indian institutes. Besides the characterization of field communities, the goal is to establish highly efficient AMF isolates which will be used to increase yields in agriculture.
We use two main approaches to characterize AMF diversity:
- Morphology: AMF spores from the field sites and from trap cultures are characterized morphologically. The trap cultures with three host plants have been set up with soil from each of the 12 field sites to obtain fresh spores of all species present. Fritz Oehl is supported in glomalean taxonomy by Ewald Sieverding (University of Hohenheim, Germany).
- Molecular identification: We use AMF-specific primers for the Internal Transcribed Spacers of the ribosomal DNA according to the identification system described by Redecker (2000). Spores and AMF within colonized roots and spores from the field and from trap cultures are characterized by polymerase chain reaction and subsequent restriction analysis and DNA sequencing.
