Piotr Boroń

High intraspecific genetic and morphological variation in the pioneer lichen Cladonia rei colonising slag dumps

This study investigates the genetic and morphological variability of the lichen Cladonia rei inhabiting strongly contaminated postsmelting slag dumps in southern Poland. Altogether, 27 C. rei samples were analysed, including 17 from a single population in one dump. The phylogenetic analysis includes samples of C. rei, outgroup species, and external sequences of Cladonia section representatives from GenBank. Comparative analysis of the internal transcribed spacer (ITS) rDNA sequences revealed the presence of 19 C. rei haplotypes overall, including several of the most frequent, of which 11 are represented by single individuals only. As many as 12 haplotypes were recorded within a single population. Three strongly supported monophyletic clades comprised of specimens from different geographical regions were recovered. Morphometric analysis showed great phenotypic variability within particular clades. Apart from a full range of previously known morphological forms of the species, an additional specific morphotype was recognised in the dumps; however, its representatives do not create a monophyletic group. High genetic variability within a single population suggests that C. rei has a great potential for colonising anthropogenic habitats. This attribute emphasises the role of this lichen as an essential pioneer in the early stages of natural regeneration of such sites.

Morphological and molecular identification and PCR amplification to determine the toxigenic potential of Fusarium spp. isolated from maize ears in southern Poland

The average amount of precipitation in spring and summer 2010 and 2011 coupled with relatively high temperatures caused massive Fusarium spp. infection of maize and yield losses in southern Poland. In order to examine the cause of this disease outbreak, Fusarium spp. were isolated and fungal strains were identified based on morphological characters and species-specific PCR assays. A total of 200 maize samples were processed, resulting in the obtention of 71 strains, which belonged to five Fusarium species, F. poae being the predominant one (74.56%). Other isolates were identified as F. graminearum, F. oxysporum, F. verticillioides and F. proliferatum. PCR-based detection of mycotoxin-synthesis-pathway genes was also used to determine the potential of the analyzed strains to produce trichothecenes (DON and NIV) and fumonisins (FUM). Only 14 isolates revealed the potential to produce DON (11 strains) and FUM (3 strains). HPLC analyses of grain samples revealed the presence of DON only – other mycotoxins were not detected. Moreover, 57.1% of potentially mycotoxin-producing isolates indicated the toxicity in a biological test.

Modifications in the structure of the lichen Cladonia thallus in the aftermath of habitat contamination and implications for its heavy-metal accumulation capacity

Phenotypic traits of lichens can be greatly modified by environmental factors. Granulose thalli on soil and podetia, densely covered with granules, referring to common and widespread lichen Cladonia cervicornis subsp. verticillata were found near zinc smelter. The granules are stratified, filled with fungal medulla and heavily encrusted with calcium oxalate weddellite crystals, not observed on regularly developed thalli of the species. Phylogenetic analysis revealed that deformed granulose forms belong to this taxon, showing that the phenotypic plasticity of the lichens of Cladonia can lead to the emergence of features that do not coincide with the taxonomic definition of the species. The heavy-metal accumulation capacity of both granulose and regular form of primary and secondary lichen thallus, in relation to the element content in corresponding substrate, was determined. Granulose-modified thalli accumulate greater amounts of heavy metals than regular ones, meaning that the bioaccumulation property of a given species may be greatly affected by morphological modifications. The granulose forms are also characterised by considerably higher ratios of Cd, Pb and As concentrations in lichen samples in relation to the corresponding substrates than regular ones. This means that collection of variously formed thalli should be avoided in biomonitoring sampling procedures. The results indicate that a substantial part of the element load, in particular zinc, in the examined lichen thalli collected near the smelter originates from atmospheric fallout.

Species composition and molecular assessment of the toxigenic potential in the population of Fusarium spp. isolated from ears of winter wheat in southern Poland

The aim of this study was to identify the species composition and to evaluate the prevalence of genes involved in the synthesis of the following mycotoxins: deoxynivalenol, nivalenol and fumonisins in the population of Fusarium spp. isolated from ears of winter wheat in southern Poland. All fungal isolates were identified by the species-specific PCR or sequencing of the translation elongation factor. Significant differences were observed in both abundance and species composition of the collected strains between two years of studies. A total of 304 ear samples were processed and 107 Fusarium strains belonging to 10 species: F. graminearum , F. culmorum , F. sporotrichioides , F. poae , F. avenaceum , F. oxysporum , F. verticillioides , F. equiseti , F. tricinctum and F. cerealis were isolated in 2012 and 2013. Numerous presence of mycotoxin-biosynthesis pathway genes was detected in the examined material, which evidences the potential toxicity of the analyzed Fusarium fungi.

Potential Microbiological Threat to the Vistula Waters by Its Tributaries in the Vicinity of Kraków

The Vistula is the longest river in Poland. It stretches from the Silesian Beskids to the Gulf of Gdansk. Water from the Vistula is the source of drinking water for many cities and is used in industry, and therefore its quality and microbiological purity is an important issue. The quality of water in the Vistula depends, among others, on the quality of water in its basin. The aim of this study is to assess microbiological hazard to the Vistula waters from its tributaries in the vicinity of Krakow. The analyses were carried out on 10 tributaries of the Vistula: Prądnik, Dlubnia, Drwina Dluga, Drwinka, Raba, Uszewka, Szreniawa, Uszwica, Kisielina, and Dunajec. The examinations were carried out in four series, from May 2012 to March 2013. The numbers of coliforms, faecal coliforms, Enterococcus faecalis , and sulphate reducing Clostridium were determined using the membrane filtration method, while the serial dilutions method was used to determine the numbers of mesophilic and psychrophilic bacteria, Staphylococcus and Salmonella . There was a large variation in the number of microorganisms in the examined watercourses, however in most cases the water could be classified as clean, whereas waters of the Vistula in the vicinity of Krakow are microbiologically contaminated. Thus, the examined watercourses do not pose a serious threat to the quality of the Vistula. Among the analyzed tributaries, the waters of the Prądnik were characterized by the worst sanitary condition, while the best microbiological quality was observed in the Dunajec.

The molecular marker-based comparison of Azotobacter spp. populations isolated from industrial soils of Cracow-Nowa Huta steelworks (southern Poland) and the adjacent agricultural soils

The occurrence of Azotobacter spp., which has beneficial effects on plant development, is related to various soil properties, such as pH and fertility. This study evaluated the prevalence of Azotobacter spp. in industrial (H) and agricultural soils (P) in Nowa Huta, Cracow and determined the phenotypic and genetic diversity of these bacteria. The examined bacteria were present in 40% of H and in 50% of P soils. Taxonomic identification of the bacterial isolates indicated the presence of three species—A. salinestris, A. chroococcum and A. vinelandii. The genetic diversity, determined using two fingerprinting methods—Random Analysis of Polymorphic DNA (RAPD) and Rep-PCR (BOX) revealed high level of population diversity. In AMOVA analysis most of diversity was attributed to within-population variation (76–85%), and only 3.78–6.18% was associated with among-group H and P variation. Global test of differences revealed distinct population structure within bacterial strains isolated from H and P areas only for BOX markers (Fst = 0.05732, P = 0.00275). Phenetic analyses: UPGMA and DCA better discriminated H and P groups based on RAPD data. Both BOX and RAPD methods provided an insight into the genetic complexity of Azotobacter spp. variation in soils of different land-use types.