The aim of this study was to investigate the effect of autochthonous microorganisms present in soil collected from heavy metal (HM) uncontaminated (Pb ≈ 59 mg kg −1 , Cd ≈ 0.4 mg kg −1 , Zn ≈ 191 mg kg −1 ), moderately (Pb ≈ 343 mg kg −1 , Cd ≈ 12 mg kg −1 , Zn ≈ 1876 mg kg −1 ), and highly (Pb ≈ 1586 mg kg −1 , Cd ≈ 57 mg kg −1 , Zn ≈ 3280 mg kg −1 ) contaminated sites on Zea mays elemental composition, physiological status, and growth parameters. For this purpose, half of the collected soil was sterilized and soil characterization was performed. After 45 days of cultivation, the presence of HM in the soil negatively affected photosynthesis and transpiration rates, relative chlorophyll content, anthocyanins index, chlorophyll fluorescence parameters, and content of oxidative stress products (H 2 O 2 and Malondialdehyde) of Zea mays , while soil sterilization had a positive effect on those parameters. Average percentage of colonization of root segments by arbuscular mycorrhiza fungi decreased with an increase of HM contamination in the soil. The increase in shoot concentration of HMs, particularly Cd and Zn, was a result of contaminated soils sterilization. Aboveground biomass of maize cultivated on sterilized soil was 3-fold, 1.5-fold, and 1.5-fold higher for uncontaminated, moderately contaminated and highly contaminated soils respectively when compared to nonsterilized soils. Contrary to our expectation, autochthonous microflora did not improve plant growth and photosynthetic performance; in fact, they had a negative effect on those processes although they did reduce concentration of HMs in the shoots grown on contaminated soils. Electronic supplementary material The online version of this article (10.1007/s11356-018-3923-9) contains supplementary material, which is available to authorized users.

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Understanding the behavior of arbuscular mycorrhizal fungi (AMF) associated with plants is essential for optimizing plant cultivation to the phytoremediation of degraded soils. The objective of the present study was to evaluate the differences in AMF root colonization between novel seed-based interspecific Miscanthus hybrids (M. sacchariflorus × M. sinensis) and the standard M. × giganteus when grown in soils contaminated with heavy metals (Pb, Cd, and Zn). During the third and fourth growing seasons, higher levels of metals in the roots and a reduced transfer of metals from the roots to the shoots were observed in all the plants studied. After the third growing season, GNT5 had the highest AMF root colonization rates in soil contaminated with heavy metals. The lowest AMF colonization rates were observed for the GNT34 hybrid. After the fourth growing season, AMF colonization decreased, which could be due to the drought that occurred during that season. GNT34 showed a lower tendency to develop mycorrhizal structures on heavy-metal (HM)-contaminated soils than GNT41 and M × g; however, this cultivar was insensitive to changes in colonization rates during the dry growing season.

Arbuscular Mycorrhizal Fungi that colonize the roots of plants growing on lands contaminated by heavy metals may influence the phytostabilization process reducing the translocation of metals to the aboveground parts of the plant. This study aimed to evaluate the effects of soil amendments (lime and lignite) on the concentration of the bioavailable form of heavy metals (CaCl2 extraction) in soil and on the colonization of Arbuscular Mycorrhizal Fungi in the roots of Lolium perenne when cultivated in contaminated soil. During the experiment, the bioavailability of Pb, Cd, and Zn in soil was significantly reduced after application of the amendments, causing an increase of L. perenne shoot dry biomass. It was observed that the higher dose of lime (0.5%) resulting in amplified values of relative mycorrhizal intensity. However, independently of the dose, the treatments increased the occurrence of arbuscules in L. perenne roots, with the highest value observed after the application of 0.25% lime with 5% lignite. The results for the first time present the effect of lime and lignite application on the L. perenne roots colonization by Arbuscular Mycorrhizal Fungi indicating the increase of occurrence of arbuscules. These findings suggest that in order to explain the different responses of Arbuscular Mycorrhizal Fungi to the applied treatment further investigations are needed to identify the spore morphology. The results of the experiment were implemented to stabilize heavy metals during remediation of a spoil heap in Ruda Śląska, Poland.