Tuber wenchuanense, a holarctic truffle with a wide range of host plants and description of its ectomycorrhiza with spruce.

Tuber wenchuanense ascomata (Ascomycota, Pezizales), a species originally described from Sichuan (China), were found in the Tatra Mountains in southern Poland. The purpose of this work was to (i) report and assess the first case of the holarctic natural distribution of a Tuber species, (ii) amend the original description of the species, (iii) summarize data on its host plants and (iv) describe its ectomycorrhiza. Specimens of Tuber wenchuanense from the Tatra Mountains were studied morphologically and molecularly. The ectomycorrhiza of this truffle with Picea abies was described for the first time. The distribution of T. wenchuanense, which is reconstructed based on sequences deposited in the publicly available nucleotide sequence databases, makes it the first holarctic Tuber species and the one with the northernmost habitat. In fact, its habitat is confined mainly to mountain coniferous forests and alpine and arctic tundra; although, according to known observations, the fruiting bodies of T. wenchuanense can be produced only under conifers. Based on the sequences of the internal transcribed spacer, this species appears to have low genetic variability over the entire distribution range. The phylogenetic tree showed that some of the unidentified phylotypes from the Rufum clade found by other researchers belong to T. wenchuanense. The ecological implications of these findings are discussed.

Identification of bacteria and fungi inhabiting fruiting bodies of Burgundy truffle (Tuber aestivum Vittad.).

Tuber species may be regarded as complex microhabitats hosting diverse microorganisms inside their fruiting bodies. Here, we investigated the structure of microbial communities inhabiting the gleba of wild growing (in stands) T. aestivum, using Illumina sequencing and culture-based methods. The two methods used in combination allowed to extract more information on complex microbiota of Tuber aestivum gleba. Analysis of the V3-V4 region of 16S rDNA identified nine phyla of bacteria present in the gleba of T. aestivum ascomata, mostly Proteobacteria from the family Bradyrhizobiaceae. Our results ideally match the earlier data for other Tuber species where the family Bradyrhizobiaceae was the most represented. The ITS1 region of fungal rDNA represented six alien fungal species belonging to three phyla. To complement the metagenomic analysis, cultivable fungi and bacteria were obtained from the gleba of the same T. aestivum fruiting bodies. The identified fungi mostly belong to the phylum Basidiomycota and same to Ascomycota. Analysis of cultivable bacteria revealed that all the specimens were colonized by different strains of Bacillus. Fungal community inhabiting T. aestivum fruiting bodies was never shown before.

Comparison of Chemical Composition in Tuber aestivum Vittad. of Different Geographical Origin.

Truffles are prized and nutrition-rich edible hypogeous fungi. The aim of this study was a comprehensive investigation of chemical composition of Burgundy truffle (Tuber aestivum Vittad.). We tried to answer the question: what is the impact of the environment on the truffle quality. To know the nutritional value of Burgundy truffle we compared lipids, proteins, saccharides, polyphenolics, flavonoids, total sterols, ergosterol, volatile flavour and aroma compounds content in fruit bodies of the fungus collected in three different geographical regions, i.e., Poland, Slovakia, and Italy. A comparison of the above mentioned compounds is especially interesting due to environmental and climatic differences among the studied geographical regions. Results revealed that fruit bodies of T. aestivum from Poland and Slovakia possessed nearly similar content of proteins, total sterols, and saccharides. The fruiting bodies from Italy contained significantly larger amounts of most of the investigated compounds. In turn, Polish specimens had higher content of lipids and polyphenolics than Slovak and Italian ones. We have found higher similarity of volatile compounds composition between Polish and Italian specimens than those of Polish and Slovak origin.

An Overview of Mycorrhiza in Pines: Research, Species, and Applications.

In the latest literature, climate models show that the conditions for pines, spruces, larches, and birches will deteriorate significantly. In Poland, as well as in other European countries, there are already signs of the decline of these species. This review article deals with the symbiotic relationships between fungi and plants, which can hardly be overestimated, using the example of pine trees. These are the oldest known symbiotic relationships, which are of great benefit to both components and can help plants, in particular, survive periods of severe drought and the attack of pathogens on the roots. This article describes symbioses and their causal conditions, as well as the mycorrhizal components of pine trees and their properties; characterizes ectomycorrhizal fungi and their mushroom-forming properties; and provides examples of the cultivation of pure fungal cultures, with particular attention to the specificity of the mycorrhizal structure and its effects on the growth and development of Pinus species. Finally, the role of mycorrhiza in plant protection and pathogen control is described.

The impact of anthropogenic transformation of urban soils on ectomycorrhizal fungal communities associated with silver birch (Betula pendula Roth.) growth in natural versus urban soils.

Betula pendula Roth. is considered a pioneering plant species important for urban ecosystems. Based on the sequencing of fungal ITS, we characterized the ectomycorrhizal (ECM) communities of twenty silver birch trees growing in a contaminated, highly anthropo-pressured urban environment and in a natural reserve site. We analysed chemical properties of each tree soil samples, focusing on effects of anthropogenic transformation. Three effects of urbanization: high heavy metal content, increased salinity and soil alkalinity, were highly correlated. The examined trees were divided into two forest and two urban clusters according to the level of anthropogenic soil change. The effect of soil transformation on the ECM communities was studied, with the assumption that stronger urban transformation leads to lower ECM vitality and diversity. The results of the study did not confirm the above hypothesis. The ECM colonization was above 80% in all clusters, but the forest clusters had significantly higher share of vital non-ECM root tips than the urban ones. Eleven mycorrhizal fungal species were identified varying from seven to nine and with seven species observed in the most contaminated urban plot. However, the lowest Shannon species diversity index was found in the most natural forest cluster. In conclusion, our findings demonstrate no significant negative effect of the urban stresses on the ECM communities of silver birch suggesting that both forest and urban trees have the potential to generate a similar set of ECM taxa.

First molecular identification of Suillia gigantea (Meigen, 1830) (Diptera: Heleomyzidae).

In 2017, the presence of the fly Suillia gigantea (Meigen, 1830) was noted in Poland, after many years of research related to the ecology of insects associated with the fruiting bodies of hypogeous fungi. Finally, in 2020, after further studies, the distribution of the truffle fly in Poland was confirmed. Six adults were reared from larvae inhabiting the fruiting bodies of Burgundy truffle (Tuber aestivum Vittad. (1831)). The fungi were harvested in southern Poland. Morphological and genetic analyses of the insect specimens were performed. For the first time, the DNA sequence of this fly species was isolated. This is the first record of S. gigantea in Poland, although it has already been reported from neighbouring countries. The development of S. gigantea, also known as the truffle fly, is associated with hypogeous fungi, mainly belonging to the genus Tuber P. Micheli ex F.H. Wigg. (1780). The diptera larvae develop inside the fruiting bodies. This type of damage causes great losses in truffle production. Containment of these losses is of great interest to the truffle industry. Knowledge of truffle-inhabiting insects is crucial for the development of effective methods to protect truffle crops in Europe.

The ectomycorrhizal community of urban linden trees in Gdansk, Poland.

The linden tree (Tilia spp.) is a popular tree for landscaping and urban environments in central and northwest European countries, and it is one of the most popular in cities in Poland. Ectomycorrhizal fungi form a symbiosis with many urban tree species and protect the host plant from heavy metals and against salinity. The aim of this study was to characterise the ECM fungal community of urban linden trees along the tree damage gradient. The study was performed on two sites located in the centre of the city of Gdansk, in northern Poland. The vitality assessment of urban linden trees was made according to Roloff's classification. Tree damage classes were related to soil characteristics using principal component analysis. The five ectomycorrhizal fungal species were shared among all four tree damage classes, and Cenococcum geophilum was found to be the most abundant and frequent ectomycorrhizal fungal species in each class. Soil samples collected in the vicinity of trees belonging to the R0 class had significantly lower pH Na, Cl and Pb content than other soils. Our knowledge of ectomycorrhizal communities in urban areas is still limited, and these findings provide new insights into ectomycorrhizal distribution patterns in urban areas.

Post-fire dynamics of ectomycorrhizal fungal communities in a Scots pine (Pinus sylvestris L.) forest of Poland.

BACKGROUND: Global warming and drying have markedly enhanced in most forests the risk of fires across the world, which can affect the taxonomic and functional composition of key tree-associated organisms such as ectomycorrhizal (ECM) fungi. The present study was conducted to characterise the alterations in the extent of root ECM colonisation, the ECM fungal communities, and their exploration types (i.e., indicator of ECM soil foraging strategies) in regenerated pines within a burned site as compared with an unburned site (five years after the fire event) in the Forest District Myszyniec, Poland. METHODS: To assess the ECM fungal communities of burned and control sites, soil soil-root monoliths were collected from the study sites in September 2019. A total of 96 soil subsamples were collected for soil analysis and mycorrhizal assessment (6 trees × 2 sites × 4 study plots × 2 microsites (north and south) = 96 subsamples). RESULTS: The percentage of root ECM colonisation was significantly lower in the burned site in comparison with the unburned (control) site. However, the ECM species richness did not differ between the control and burned sites. The identified ECM species in both sites were Imleria badia, Thelephora terrestris, Russula paludosa, R. badia, R. turci, R. vesca, Lactarius plumbeus, Phialocephala fortinii, and Hyaloscypha variabilis. The most frequent species in the burned and control sites were I. badia and T. terrestris, respectively. The relative abundances of contact, medium-distance smooth and long-distance exploration types in the burned site were significantly different from the control site, dominated by the medium-distance exploration type in both sites. The abundance of the long-distance exploration type in the burned site was markedly greater (27%) than that of the control site (14%), suggesting that the fire event had favoured this ECM foraging strategy. The results demonstrated that the fire led to reduced ECM colonisation of Scots pine trees in the burned site whereas the species richness was not affected, which can be attributed to degrees of fire-resistance in the ECM species, survival of ECM propagules in deeper soil layers, and/or continuous entry of spores/propagules of the ECM fungi from the adjacent forests via wind, water run-off or animals.

Truffle renaissance in Poland - history, present and prospects.

The use of truffles in Poland has a long tradition, yet due to some historical aspects, this knowledge was lost. Currently, truffles and truffle orchards are again receiving attention, and thanks to, e.g., historical data, they have solid foundations to be established. Publications relating to truffles between 1661 and 2017 were searched for in international and national databases, such as the database of PhD theses, Google Scholar, and catalogues of the National Library of Poland, the Jagiellonian Digital Library, the University Library of J. Giedroyc in Bialystok and the Lower Silesian Digital Library (DBC). A very meticulous survey of the literature on truffles showed that truffles have been known since at least 1661. In the 18th century, the fungi were considered a non-timber forest product. It is interesting to mention the impact of Polish Count Michal Jan Borch in understanding the nature of truffles. The whitish truffle (Tuber borchii) is named after him. The greatest number of publications regarding truffles can be observed at the first half of the 19th and 20th centuries. The fungi were present not only in cookbooks but also in scientific literature, and aspects of their ecology and medicinal use are considered. The "dark ages" for truffles, mainly for social reasons, occurred after the Second World War. In tough times, when Poland was under Soviet communist control (1945-1989), truffles as a luxurious product have been completely forgotten. However, at the end of the 20th century, truffles started receiving attention in Polish society. Yet, the real awakening began in the first decade of the twenty-first century when the first truffle orchards were established. One of them has already produced the first fruit bodies of summer truffle (Tuber aestivum). Truffles have been present in Polish culture for centuries. Their renaissance indicates the need for fostering sustainable agroforestry-centred initiatives aimed at helping truffle growers in growing the precious fungi and thus meeting market demands.

New tuber species found in Poland.

New information from a survey of truffles carried out in southern part of Poland in September 2007 is presented. The fruit bodies of Tuber aestivum, T. excavatum, T. rufum and one unidentified Tuber sp. were found. The soil chemistry of the five T. aestivum sites was analysed. Our inventory showed that T. aestivum prefers the mixed forest with host-trees such as: Quercus robur, Corylus avellana, Carpinus betulus, Fagus silvaticus and Tilia cordata. Selection of local inocula of T. aestivum for the propagation of truffles production could be an alternative to the Mediterranean truffles orchards in times when demand for the fungi will be increasing. Fruit bodies of truffles are conserved in the collection of biological material in the Forest Research Institute in Sekocin Stary.