Elena Salerni

Effects of temperature and rainfall on fruiting of macrofungi in oak forests of the Mediterranean area

The results of a study on the effects of weather (rainfall and minimum, mean, and maximum temperatures) on fruiting of macrofungi in a number of oak forests of Tuscany (central Italy) are reported. The fungal parameters (total number of species and total number of carpophores) were examined for statistical correlations with annual and seasonal temperature and rainfall and with temperature and rainfall in the 5-, 10-, 15-, and 30-day periods before the date of the sampling. It was found that abundant annual rainfall was necessary for the fungal mycelium to fruit. Spring rainfall in particular seemed to be related to the number of species found in autumn. Rainfall was the main influence on fruiting in the most important fruiting period (autumn). Highly significant correlations were found between the number of carpophores and rainfall in the 30 days preceding sampling.

Assessment of ectomycorrhizal fungal communities in the natural habitats of Tuber magnatum (Ascomycota, Pezizales)

The ectomycorrhizal (ECM) fungal communities of four natural Tuber magnatum truffle grounds, located in different Italian regions (Abruzzo, Emilia-Romagna, Molise, and Tuscany), were studied. The main objective of this study was to characterize and compare the ECM fungal communities in the different regions and in productive (where T. magnatum ascomata were found) and nonproductive points. More than 8,000 (8,100) colonized root tips were counted in 73 soil cores, and 129 operational taxonomic units were identified using morphological and molecular methods. Although the composition of the ECM fungal communities studied varied, we were able to highlight some common characteristics. The most plentiful ECM fungal taxa belong to the Thelephoraceae and Sebacinaceae families followed by Inocybaceae and Russulaceae. Although several ectomycorrhizas belonging to Tuber genus were identified, no T. magnatum ectomycorrhizas were found. The putative ecological significance of some species is discussed.

Fungal biodiversity and in situ conservation in Italy.

Abstract A remarkable increase in knowledge of fungal biodiversity in Italy has occurred in the last five years. The authors report up-to-date numbers of fungi (Basidiomycota and Ascomycota) by regions together with distributional and ecological data on hypogeous fungi. Specific case studies such as alpine fungi, orchid mycorrhizas symbionts, invasive species, and the use of macrofungi as food by red squirrels are analyzed. In situ conservation strategies carried out on target species and/or taxonomic groups are also indicated.

Periodicity, fluctuations and successions of macrofungi in fir forests (Abies alba Miller) in Tuscany, Italy

Abstract The present study, carried out in natural and planted Abies alba Miller woods, was undertaken as a contribution to knowledge of temporal changes occurring in fungal communities. Moreover, notes on fungal species and fungal communities in this type of wood are given. Correlations between meteorological variables and fungi (number of species and number of carpophores, as total or divided into trophic groups) were tested by Pearson’s product-moment coefficient. On a short time scale, weather parameters clearly play a major role, affecting periodicity and fluctuations; on a long time scale (10 years or more), correspondence analysis (CA) indicate that vegetation parameters and forest evolution affect successions.

Spatio-temporal dynamic of Tuber magnatum mycelium in natural truffle grounds.

Tuber magnatum produces the worlds most expensive truffle. This fungus produces very rare ectomycorrhizas which are difficult or even impossible to detect in the field. A “real-time” PCR assay was recently developed to quantify and to track T. magnatum mycelium in soil. Here, this technique was used to investigate the spatial distribution of T. magnatum extra-radical mycelium in soil productive patches and its dynamic across seasons. This study was carried out in four different natural T. magnatum truffle grounds located in different Italian regions. During the fruiting seasons, the amount of T. magnatum mycelium was significantly higher around the fruiting points and decreased going farther away from them. Moreover, T. magnatum mycelium inside the productive patches underwent seasonal fluctuations. In early spring, the amount of T. magnatum mycelium was significantly higher than in summer. In summer, probably due to the hot and dry season, T. magnatum mycelium significantly decreased, whereas in autumn it increased again and was concentrated at the putative fruiting points. These results give new insights on T. magnatum ecology and are useful to plan the most appropriate sampling strategy for evaluating the management of a truffle ground.

Development and validation of a real-time PCR assay for detection and quantification of Tuber magnatum in soil

BackgroundTuber magnatum, the Italian white truffle, is the most sought-after edible ectomycorrhizal mushroom. Previous studies report the difficulties of detecting its mycorrhizas and the widespread presence of its mycelium in natural production areas, suggesting that the soil mycelium could be a good indicator to evaluate its presence in the soil. In this study a specific real-time PCR assay using TaqMan chemistry was developed to detect and quantify T. magnatum in soil. This technique was then applied to four natural T. magnatum truffières located in different regions of Italy to validate the method under different environmental conditions.ResultsThe primer/probe sets for the detection and quantification of T. magnatum were selected from the ITS rDNA regions. Their specificity was tested in silico and using qualitative PCR on DNA extracted from 25 different fungal species. The T. magnatum DNA concentration was different in the four experimental truffières and higher in the productive plots. T. magnatum mycelium was however also detected in most of the non-productive plots. Ascoma production during the three years of the study was correlated with the concentration of T. magnatum DNA.ConclusionsTaken together, these results suggest that the specific real-time PCR assay perfected in this study could be an useful tool to evaluate the presence and dynamics of this precious truffle in natural and cultivated truffières.

Wild and cultivated mushrooms as a model of sustainable development

The natural resources are currently overexploited and since 1992 the Conference of Rio de Janeiro has focused on sustainable development to safeguard our planet for future generations. The Fungi kingdom includes producers of goods and services for ecosystems and organisms widely used in the food industry. Besides, macrofungi are recognized as non-timber forest products and could be utilized as agents of environmental management through weed biocontrol and environmental improvement. Moreover, the cultivation of fungi, in particular truffles, can provide an important income in agroecosystems, especially in marginal areas, along with the development of new technologies to produce novel products from fungi.

Mycocoenologial studies in deciduous oak woods of central-southern Tuscany (Italy)

We report results of a mycocoenological study in deciduous oak woods growing on different lithological substrates (siliceous and calcareous) in central-southern Tuscany. The data obtained are analysed in relation to environmental parameters to determine their influence on the composition of fungal communities in the study areas.

Mycofloristic investigations in the geothermal area of Travale-Radicondoli (Tuscany, central Italy)

Summary Mycofloristic investigations have been carried out in deciduous oak-woods in the geothermal area of Travale-Radicondoli (Tuscany, Central Italy). 235 fungal species (Ascomycota and Basidiomycota) have been identified during 3 observation years; some of these are uncommon or rare, some others have never been cited for the Province of Siena. From this study emerges that geothermal activity seems to be less polluting than other types of industries or power stations.

Interrelationships Between Wild Boars ( Sus scrofa ) and Truffles

The European population of wild boars has increased considerably since the 1960s, leading to increased damage to agroecosystems. Their distribution coincides with the natural distribution of the most important commercial Tuber species. In this chapter, the truffle/wild boar interrelationships are discussed and include the importance of truffles in their diet, their role in spore dispersal, and their impact on cultivated truffieres. Wild boars eat a wide variety of foods: plant matter, animals, fungi, bulbs, tubers, and roots. Analyses of their feces and stomach contents suggest they can be considered casual or opportunistic mycophagists, with fungal consumption simply dependent on the availability of other foods. The ingestion of hypogeous fungi is more frequent than that of epigeous mushrooms. Their rooting behavior primarily reduces plant cover and diversity, affects the first 15–70 cm of the litter layer, and can damage up to 80 % of the forest soil surface. Excavation may cause great economic losses to cultivated truffieres, not only in terms of truffle predation but also through soil disturbance so that there can be significant increases in truffle production after fencing cultivated truffieres damaged by wild boars. Because wild boars can move as much as 15 km in a day, they efficiently contribute to long-distance dispersal of truffle spores. Moreover, the action of the degradation of the digestive enzymes on asci and spore wall improves germination and the ability to form ectomycorrhizas and results in wild boars playing a pivotal role in truffle colonization of new habitats.