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The rhizosphere is the region of soil in which the highest densities of fungi and bacteria occur. In this study, an attempt was made to assess the distribution of bacterial species in soil where the summer truffle Tuber aestivum Vittad. bears fruit in selected stands in Poland. In order to determine the bacterial metagenome, the Next Generation Sequencing (NGS) method was applied. Differences occurred in the bacterial species composition at the cluster level between soils in which summer truffle fruiting was recorded and control soils. In particular, differences in the percentage of Firmicutes bacteria were noted with an average frequency of 3.9% in truffle soil compared to 96.1% in the control soil. It was estimated that two bacterial species, namely Lysobacter antibioticus and Ensifer adhaerens had a positive effect on the occurrence of T. aestivum. Our research increased the knowledge of particular groups of bacteria accompanying truffles and their potential impact on the formation of fruiting bodies in T. aestivum.

This paper continues the studies on the role of bacteria in the environment of summer truffle (Tuber aestivum) (soil and roots), focusing on ascomata at three sites in the Nida Basin (southern Poland). Bacterial species and the number of OTU sequences identified were determined based on analysis of peridium and gleba contamination collected in 2017 and 2018. Both the classical culture method with qualitative analyses, i.e., Sanger DNA sequencing, and next-generation sequencing (NGS) were used. In addition, the PERMANOVA test and alpha and beta biodiversity indicators were used. Of the individual bacterial colonies, 140 were used for further molecular analyses. The Sanger method identified six bacterial genera that were dominant in the community: Bacillus, Pseudomonas, Stenotrophomonas, Paenibacillus, Rhizobium, and Chryseobacterium, of which Bacillus (86.7%) and Pseudomonas (51.5%) were the most abundant. In contrast, NGS results showed the dominance (at OTUs > 10,000) of representatives of eight families, mainly Bradyrhizobiaceae, Sphingobacteriaceae, Micrococcaceae, Yersiniaceae, Sphingomonadaceae, Rhizobiaceae, Flavobacteriaceae, and Comamonadaceae. The PERMANOVA test for the Bray-Curtis and Jaccard indices showed dissimilarities between samples from sites G and W with respect to beta diversity. Significant differences were found in the bacterial communities colonising the ascomata of T. aestivum and in the root communities with T. aestivum ectomycorrhizae of the tree adjacent to the ascomata. The number of OTUs at the species level was 69 in the roots and 212 in the shoots. Our study allowed us to determine the bacterial microbiome in the ascomata of T. aestivum, leading to a better understanding of the preferences of certain groups of truffle-associated bacteria and how they relate to the presence of truffle ascomata under specific habitat conditions. The results obtained may be useful in selecting and monitoring sites suitable for the formation of ascomata of T. aestivum.

In this study, we examined the effect of the presence of mycorrhiza and ascomata of summer truffle (Tuber aestivum) on the bacterial composition of roots from small trees growing in selected sites of the Nida Basin. Qualitative DNA sequencing methods such as Sanger and next-generation sequencing (NGS) were used. The Sanger method revealed different bacterial species compositions between the samples where summer truffle ascomata was recorded and control samples. Five genera of bacteria could be distinguished: Bacillus, Erwinia, Pseudomonas, Rahnella and Serratia, among which the most numerous were Pseudomonas (Gammmaproteobacteria class) at 32.9%. The results obtained by the NGS method also showed differences in species composition of the bacteria depending on the study sample. Seven genera of bacteria were distinguished: Rhizorhabdus, Methylotenera, Sphingomonas, Nitrosospira, Streptomyces, Methyloceanibacter and Niastella, which dominated in roots from the truffle sites. Telmatobacter, Roseiarcus, Granulicella, Paludibaculum, Acidipila, Acidisphaera and Aliidongia dominated in roots from the control sites. With the NGS method, it is possible to identify the microbiome of a whole root, while only a root fragment can be analysed by the Sanger method. These results extend the scope of knowledge on the preferences of certain groups of bacteria associated with truffles and their influence on the formation of ascomata in summer truffles. Our results may also be useful in selecting and monitoring sites that promote ascomata of Tuber aestivum.

This paper describes the quantitative and qualitative composition of bacteria isolated from soil in the selected sites in the Nida Basin, in places where mycorrhizae and ascocarps of summer truffle (Tuber aestivum) were found, and in a control soil (without truffle). A classic growth culture method was used with Sanger DNA sequencing to obtain quantitative and qualitative measures of bacterial cultures. The obtained results showed differences in bacteriome composition between the case samples, in which summer truffle fructification was observed, and the control samples. Seven classes of bacteria were identified: Actinobacteria, Bacilli, Deinococci, Flavobacteria, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. The most numerous bacterial genera were Pseudomonas (class Gammaproteobacteria) – 33%, Streptomyces (class Actinobacteria) – 29% and Bacillus (class Bacilli) – 15%. This research broadens the understanding of individual groups of bacteria accompanying truffles and their potential impact on the formation of summer truffle ascocarps.

While the use of truffles in Poland has a long tradition, for historical reasons this knowledge was almost lost. Currently, truffles and truffle orchards are again receiving public attention. For example, the Polish State Forests supported the establishment of truffle orchards by the Forestry Research Institute. In recent years, knowledge concerning these unique hypogeous fungi has been disseminated systematically through scientific and popular publications, films, and electronic media. This study investigates the awareness of economically and culinary valued truffle fungi (Tuber spp.) among more than 1400 Polish foresters. The results show that 70% of interviewees were familiar with historical and contemporary information about growing and using truffles in Poland. Based on respondents&rsquo, age, education, type of work, and gender we attempted to identify whether these elements were associated with the state of knowledge about truffles. The results indicated that younger foresters were better informed about the presence of truffles in Poland and also about their use in the past in Polish cuisine. Environmental education was an important source of knowledge about truffle harvesting and the soils that are conducive to truffle development. Foresters who have provided forest ecology education and who are 36&ndash, 65 years of age generally possessed better knowledge about truffles than other age cohorts. More than 30% of respondents expressed interest in educational courses to improve their knowledge of truffles. The results point to the need for forestry education concerning truffles and indicate the need for fostering sustainable agroforestry-centered initiatives disseminating this knowledge to the public.

Forest decline induced by Phytophthora is a global phenomenon that affects many tree species. In central Europe, the health of Quercus robur has been declining due to various biotic and abiotic factors, since the 2000s. In drought-prone areas in the Mediterranean region, forests of Q. ilex show maintained tree mortality since the 1980s. The efficacy of potassium phosphite, applied as a foliar or trunk spray at a range of concentrations between 0 and 35%, was investigated over several years in four field trials with mature oaks. Specifically, Experiments 1 and 2, conducted on Q. robur in Poland indicated that aerial and trunk spray of 35% phosphite improved the crown condition of unhealthy trees. The efficacy of treatments was not dependant on the initial tree health condition, although its effects started earlier in trees that had lower crown transparency. Treatments did not alter the abundance and composition of edaphic and endophytic bacteria of trees. Moreover, aerial spray enhanced the N, P and Mg leaf content and induced the formation of fine roots without compromising the secondary growth of trees. In Experiment 3, conducted in Spain on Q. ilex, foliar spray did not improve the crown condition of trees. However, foliar spray of 0.56% phosphite induced twig growth in treated trees located on a southern exposure. Reduction of Phytophthora inoculum by the use phosphite was not observed. Our study provides the foundation for the development of a cost-effective management tool for Phytophthora in Europe and motivates future research into the optimization of treatments in Q. ilex and Q. robur.

This study is designed to test the potential for reducing the growth of the mycelium of the fungus Hymenoscyphus fraxineus (anamorph Chalara fraxinea) by using phosphite preparations at various concentrations in vitro. The study shows that adding pure phosphite to potato dextrose agar media inhibits the development of the fungus, but if the preparation is applied in the form of ammonium phosphite (Actifos), the growth of fungus will be accelerated. Probably the addition of nitrogen contained in the product Actifos has positive effect on the mycelial growth, but pure phosphite restricts its development. These studies are preliminary and only show the potential use of phosphite to reduce the development of H. fraxineus; however, to completely confirm its operation, further research is needed in this area.

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.

Slow Sand Filters (SSF) are a biological method used to protect nursery plants, from pathogen infections which can cause serious diseases in many forest tree species. Thanks to SSF application the number of phytopathogens in nurseries can be significantly reduced, as demonstrated by many field and greenhouse experiments (e.g. in Polish nurseries, and for horticultural crops in Germany and The Netherlands). In this study, the effect of pollution from fertilizers and fungicides used in agriculture (e.g. PCNB) on the efficiency of SSFs was assessed. A quantitative analysis was performed of the copiotrophic and oligotrophic bacterial composition colonizing SSF biofilms. The efficiency with which selected Oomycete strains belonging to the genus Phytophthora (P. alni, P. cactorum, P. plurivora) were removed from water was determined based on genetic material (DNA of the organisms) found in the SSF filtrate. Specific primers and TaqMan probes (qPCR) appeared to be the most sensitive molecular methods. Moreover, the microbiological analysis of SSF biofilm performed with selective media allowed the growth of copiothrophic and oligothrophic bacteria to be estimated. The influence of fungicide (PCNB) and N-fertilizer on the number of bacteria in each biofilm was also evaluated. The pollution of water with fertilizer (being used for plant irrigation) was demonstrated to reduce the efficiency of filtration more than fungicide addition (the amount of DNA from those investigated pathogens in the water decreased with time). The amount of bacteria in SSF biofilm readily increased after application of N-fertilizer in contrast to fungicide (PCNB) addition.

Truffles (Tuber spp.) are ascomycete hypogeous fungi, which form ectomycorrhizae with roots of trees, shrubs and herbaceous plants. Their fruiting bodies are valued for their distinctive aroma. The aroma might be partially due to complex bacterial community which colonizes their fruiting bodies. Some bacterial species are also believed to promote the truffle’ fruitification due to the fixation of nitrogen inside the developing truffles. Although truffles, especially of the species Tuber aestivum, are getting more popular and are widely cultivated, little is still known about their biology, composition and the role of their associative microbes. The aim of this study was to present the current knowledge about the bacterial communities associated with black truffles and their potential influence on the truffle life cycle and maturation. 1. Characteristics of truffles. 2. Diversity of bacterial species. 3. Conclusion 1. Charakterystyka trufli. 2. Różnorodność gatunkowa bakterii. 3. Podsumowanie