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Two selected examples of PIXE microanalysis in ecophysiology are presented. Studies of heavy metal distributions in mycorrhizal and non-mycorrhizal roots of Plantago lanceolata showed different filtration mechanisms of Zn/Pb and Fe/Mn, both enabling plants to cope with metals present in the environment. Studies of the mechanism used by the beetle Chrysolina pardalina to eliminate excessive amounts of Ni revealed that Malpighian tubules are responsible for the elimination of this metal from the hemolymph.In both examples GeoPIXE software was used for true elemental mapping using the Dynamic Analysis method and analysis of spectra from selected micro-areas. Specimen thickness and matrix composition were obtained from proton backscattering spectra.

Arnica montana is a rare plant that needs special protection because of its intensive harvesting for medicinal purposes. The present work was aimed at finding optimal culture conditions for Arnica plants in order to enable their successful reintroduction into their natural stands. Plants were cultivated under controlled greenhouse conditions on substrata with different nitrogen (N) concentration. As Arnica is always colonized by arbuscular mycorrhizal fungi (AMF) in nature, a fact that has been overlooked in other similar projects, we, here, applied and tested different inocula. We found that they differed in their effectiveness, both in establishing symbiosis, assessed by the colonization parameters, and in improving the performance of Arnica, evaluated by the photosynthetic parameters derived from the fluorescence transients (JIP-test), with the inocula containing G. intraradices or composed of several Glomus strains being the most effective. The comparison was possible only on substrata with medium N, since high N did not permit the formation of mycorrhiza, while at low N, few nonmycorrhizal plants survived until the measurements and mycorrhizal plants, which were well growing, exhibited a high heterogeneity. Analysis of secondary metabolites showed clearly that mycorrhization was associated with increased concentrations of phenolic acids in roots. For some of the inocula used, a tendency for increase of the level of phenolic acids in shoots and of sesquiterpene lactones, both in roots and in shoots, was also observed. We also studied the interactions between A. montana and Dactylis glomerata, known to compete with Arnica under field conditions. When specimens from both species were cultured together, there was no effect on D. glomerata, but Arnica could retain a photosynthetic performance that permitted survivability only in the presence of AMF; without AMF, the photosynthetic performance was lower, and the plants were eventually totally outcompeted.

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Paraglomus majewskii sp. nov. (Glomeromycota) is described and illustrated. It forms single spores, which are hyaline through their life cycle, globose to subglobose, (35-)63(-78) μm diam, sometimes egg-shaped, 50-70 × 65-90 μm, and have an unusually narrow, (3.2-)4.6(-5.9) μm, cylindrical to slightly flared subtending hypha. The spore wall of P. majewskii consists of an evanescent, short-lived outermost layer, a laminate middle layer, and a flexible innermost layer, which adheres tightly to the middle layer. None of the spore wall layers stain in Melzer's reagent. In single-species cultures with Plantago lanceolata as the host plant P. majewskii formed arbuscular mycorrhizae staining violet in trypan blue. P. majewskii has been isolated from several, distant geographic regions and from different habitats. In phylogenetic analyses of partial nrDNA SSU and LSU sequences the fungus formed mono-phyletic group with Paraglomus species; however it represents a well separated distinct lineage. Its nrDNA sequences are highly similar to in planta arbuscular mycorrhizal fungal sequences from different habitats in Spain and Ecuador.