5th RTD Framework Programme

Most of the higher plants are colonised by mycorrhizal fungi, as beneficial microbes in the root-systems. These fungi are known to alleviate the abiotic environmental stress conditions and they are able to confer their tolerances to the higher plants, the macrosymbionts. In this project, both ecto- (EMF) and endo- (arbuscular mycorrhizal fungi – AMF) are being isolated as single strains. Their impacts are being studied in conferring the stress-tolerant abilities to the macro-symbionts. The suitability of phyto-remediation technologies are being studied both in the greenhouse and at selected field sites. The most efficient isolates will be used for demonstration projects in soils polluted by heavy metals, polycyclic aromatic hydrocarbons (PAH) and also in natural salt-affected soils. The mechanisms of the stress-tolerant abilities are also studied both at the micro- and the macrosymbionts.

- To study the impact of AM fungi and their attached microorganisms on the heavy metal uptake and the tolerance-abilities of the higher plants. The background is a long-term field experiment, where 13 heavy metals (Al, As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, se, Sr, Zn) were given into the calcareous loamy soil 10 years ago in four levels. This polluted area can serve as modell-experiment for the EU countries to study the plant-fungal-microbe interactions and the development of metal-adaptation procedures at various metal-concentrations with various beneficial microbes (microsymbionts, PGPR Pseudomonads).

- Interrelations between the AM fungi and the other so called "helper" microbes (obligate and associative nitrogen-fixers, Trichoderma fungi, P-mobilizers) in the rhizosphere of higher plants (Rhizobiology) among various soil-circumstances. In these experiments the single or cumulative effects of AM fungi and the other rhizosphere components are studied. Other additional data about the persistence, effectivity and functioning of the indigenious microflora or AM fungi will be helpful for developing the appropriate soil-quality indications on the polluted or stressed ecosystems.

- To investigate the role of AM fungi on various natural salinic soils in Hungary (Figure 1). Plants of salt affected soils can be heavily colonized by AM fungi (Figure 2), the number of mycorrhizal spores can be also extremely high in the rhizosphere of halophytes. The salt-resistant abilities of AM fungal isolates are studied, and their contribution on the stress-alleviation of dominant halophytes among the different salinic-conditions on the Hortobagy and Kiskunsag region (with various types of saline-specific-anions, such as HCO₃^-, SO4₂^-, PO₄^- etc. beside the most common chlorides in Europe). The beneficial interrelations between the AMF colonisation and the abundance of other rhizosphere components are being demonstrated in correlation with the versatility of salinic conditions and soil-types in the project.

- The participants are shown in the Fig. 3. during the demonstration of an artificially inoculated trufle orchard in South France, at 26th of June 2002. augusztus 26.