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Second-generation biofuel crop miscanthus is one of the most promising plants tested for phytomanagement of contaminated sites. In this preliminary pot case study, the most used hybrid Miscanthus x giganteus was cultivated in three different real contaminated soils: agricultural soil contaminated with Cd, post-military soil slightly contaminated with Zn, Pb and Cd, and soil contaminated by petroleum industry with metals and hydrocarbons. The stress response of plants and soil microbial communities was monitored to receive data that are important for successful phytomanagement application. With metals only, the plant grew well, and chlorophyll fluorescence measurement proved their good vitality. Changes in leaf anatomy (leaf thickness and sclerenchyma cells area) were additionally determined in post-military soil compared to agricultural. On the contrary, in petroleum-contaminated soil, the biomass yield was too reduced and also physiological parameters were significantly decreased. The response of microbial communities also differed. In agricultural soil, no microbial stress was determined. In post-military soil, it became reduced during the experiment, and in petroleum contamination, it increased year-on-year. It could be concluded that miscanthus is suitable for cultivation in metals contaminated soils with potential for microbial communities support, but in soil contaminated by the petroleum industry, its application did not seem meaningful.

Background: To determine the level of plant stress of second-generation biofuel crop Miscanthus x giganteus ( Mxg ) grown in poor quality post-military soils using physiological parameters; to identify impact of plant growth regulators (PGRs) on the stress reduction and to select the fluorescence indicators most suitable for quantification of stress. Plant fitness was quantified with non-invasive measurement of leaf fluorescence using 16 different indexes. Simultaneously visible stress signs were observed on stems and leaves and differences were revealed by microscopy of leaf sections. Results: Leaf fluorescence analysis, visual observation and changes of leaf anatomy revealed significant stress in all tested subjects . Besides commonly used F v /F m and P.I. (performance index), the fluorescence parameter T fm (time to achieve maximum fluorescence) seems to be rather sensitive and applicable for revealing finer differences. However, none of investigated parameters proved significant positive effect of PGRs on stress reduction. Conclusions: Measuring F v /F m , P.I., and T fm is a suitable method for revealing stress affecting Mxg in poor post-military soils. Since PGRs application did not reduce the stress level, direct application of soil amendments should be considered for stress reduction and improving the biomass quality.