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Genome duplication is associated with multiple changes at different levels, including interactions with pollinators and herbivores. Yet little is known whether polyploidy may also shape belowground interactions.Methods: To elucidate potential ploidy‐specific interactions with arbuscular mycorrhizal fungi (AMF), we compared mycorrhizal colonization and assembly of AMF communities in roots of diploid and tetraploid Centaurea stoebe s.l. (Asteraceae) co‐occurring in a Central European population. In a follow‐up greenhouse experiment, we tested inter‐cytotype differences in mycorrhizal growth response by combining ploidy, substrate, and inoculation with native AMF in a full‐factorial design.Key Results: All sampled plants were highly colonized by AMF, with the Glomeraceae predominating. AMF‐community composition revealed by 454‐pyrosequencing reflected the spatial distribution of the hosts, but not their ploidy level or soil characteristics. In the greenhouse experiment, the tetraploids produced more shoot biomass than the diploids did when grown in a more fertile substrate, while no inter‐cytotype differences were found in a less fertile substrate. AMF inoculation significantly reduced plant growth and improved P uptake, but its effects did not differ between the cytotypes.Conclusions: The results do not support our hypotheses that the cytotype structure in a mixed‐ploidy population of C. stoebe is mirrored in AMF‐community composition and that ploidy‐specific fungal communities contribute to cytotype co‐existence. Causes and implications of the observed negative growth response to AMF are discussed.

Soil chemical properties. Data represent means and standard errors from four time points (n = 24). (PDF 11 kb)

A) Daily mean temperatures in 5 cm soil depth in course of the year. The arrows indicate approximate soil sampling date. B) Monthly and yearly mean temperatures in degrees of Celsius in 5 cm soil depth in control and snow-manipulated dry and wet tundra sites. (PDF 315 kb)

Identification of the 30 most abundant bacterial OTUs from dry and wet tundra soil according to SILVA database, their relative abundance in control (C) and snow manipulated plots (S) across the plant growing seasons (June, July, September and October) and seasonal average (SA). Data of relative abundance are expressed as means from 6 (24 for SA) replicates, standard errors are shown in italic. Statistically significant differences between control and snow manipulated plots in the individual seasons are highlighted (DESeq2, Benjamini-Hochberg correction, p

Venn diagrams showing shifts in (a) fungal and (b) bacterial community composition. Proportion of shared and unique OTUs across four time points is displayed (n = 24). OTUs with > 0.01% abundance were considered as present. D-dry tundra, W-wet tundra, C-control, S-snow manipulation. (PDF 53 kb)

OTU accumulation curves expressed as the number of OTUs by number of reads from sequencing. (PDF 307 kb)

Relative abundance of archaea in prokaryotic sequence pool in dry (A) and wet (B) tundra soil in control (green) and snow-manipulated (red) plots by season and as a seasonal average (SA). The data represent the means with standard errors (n = 6), for seasonal average (n = 24). (PDF 57 kb)

Identification of the 30 most abundant fungal OTUs from dry and wet tundra soil according to UNITE database, their relative abundance in control (C) and snow manipulated plots (S) across the plant growing seasons (June, July, September and October) and seasonal average (SA). Data of relative abundance are expressed as means from 6 (24 for SA) replicates, standard errors are shown in italic. Statistically significant differences between control and snow manipulated plots in the individual seasons are highlighted (DESeq2, Benjamini-Hochberg correction, p

Heatmap depicting the relative abundances of the 20 most dominant fungal genera in dry (a) and wet (b) tundra soil in control (C) and snow-manipulated (S) plots across the seasons. The data represent mean abundances (n = 6). Statistically significant effect (DESeq2, Benjamini-Hochberg correction, P

Proportion of sequences belonging to different bacterial functional groups in dry (D) and wet (W) tundra soil in control (C) and snow-manipulated (S) plots. The data represent the means with standard errors (n = 6). (PDF 51 kb)

In forest ecosystems, substantial part of carbon enters soil in the form of plant litter. The decomposition of litter and soil organic matter represents an important process affecting nutrient cycling and carbon balance in soils. Fungi are considered the primary decomposers in terrestrial ecosystems due to the production of wide range of extracellular enzymes that allow them to attack the lignocellulose matrix in litter. Even if fungi represent key players in organic matter decomposition, the information about the structure and diversity of their communities is still limited and the roles of individual fungal taxa in forest soils remain unclear. This Ph.D. thesis focused on the characterization of fungal communities in forest soils and their potential to decompose plant litter. The method for in-depth analysis of complex microbial communities from environmental samples was established and used. In addition, single eukaryotic functional gene was analysed in soil for the first time at a depth that allowed reliable estimation of diversity. It was demonstrated that microbial community composition differs among horizons of forest soil profile. Despite similar diversity, significant differences in microbial community composition were observed between the DNA and RNA. Several microbial groups highly...

We have monitored the DNA damage induced by tumor chemotherapy. The combination of platin derivate (cis-platine or carboplatin) and another chemotherapy agent (gemcitabin, paclitaxel or vinorelbin) was applied to patients with lung carcinoma. The whole chemotherapy includes 4 cycles. We have monitored the DNA damage in peripheral blood lymphocytes through the first and the third cycle of chemotherapy and 3 weeks after the last cycle of chemotherapy. For detection we have used comet assay which seems to be accurate and reliable method. Lymphocytes were isolated from whole blood through the medium LSM lymfocyte and then were processed by the alkaline version of the single cell gel electrophoresis. We have analysed single strand breaks (SSB) and interstrand cross links (ICL). For the measurement of ICL isolated lymphocytes were incubated in the presence of 200 µM of styrene oxide (SO) to degrade the DNA by inducing strand breaks. Incubation of peripheral blood lymphocytes with 200 µM SO leads to the formation of comets. If ICLs are present in the DNA, the alkaline unwinding of DNA is blocked and the % of DNA in tail is reduced. Comets were stained with ethidium bromide and then analyzed by the software LUCIA Comet Assay. The damage of DNA caused by SSB before the chemotherapy was relatively low and...