Comparison of ectomycorrhizal communities in natural and cultivated Tuber melanosporum truffle grounds

Abstract

Truffles are hypogeous ectomycorrhizal (EM) fungi belonging to the genus Tuber. Although outplanting of truffle-inoculated host plants has enabled the realization of productive orchards, truffle cultivation is not yet standardized. Therefore, monitoring the distribution of fungal species in different truffle fields may help us to elucidate the factors that shape microbial communities and influence the propagation and fruiting of Tuber spp. In this study, we compared the fungal biodiversity in cultivated and natural Tuber melanosporum truffle fields located in Central Italy. To this end, ectomycorrhizas (ECM) and soil samples were molecularly analyzed, and an inventory of the fungi associated with Quercus pubescens plants colonized by T. melanosporum, Tuber aestivum or Tuber brumale was compiled. T. melanosporum and T. aestivum were dominant on the cultivated plants, and the number of EM species was markedly lower in the cultivated sites than in the natural sites. However, in the same site, EM biodiversity was higher in T. brumale-colonized plants than in T. melanosporum-colonized plants. These results suggest that different Tuber spp. may have different competitive effects on the other mycobionts. Additionally, in keeping with our previous findings, we found that the number of T. melanosporum genotypes recovered from the soil samples was higher than that of the underlying ECM.

Ectomycorrhizal communities in a Tuber aestivum Vittad. orchard in Poland

“…Thelephoraceae species are common morphotypes on root tips in boreal forests [45] and in environments of truffle production [16,[34][35][36]39,41,47]. The genus Tomentella is widespread in orchards with Tuber spp.…”

“…The genus Tomentella is widespread in orchards with Tuber spp. [16,34,36,37,39,41,47]. Additionally, the species Cenococcum geophilum is a well-known cosmopolitan ectomycorrhizal fungus living in a wide range of environmental conditions [48,49] and is very abundant in truffle plantations [37].…”

Shifts in soil fungal communities in Tuber melanosporum plantations over a 20-year transition from agriculture fields to oak woodlands

“…With the appearance of the truffle brûlé at 5 to 7 years in these plantations, the management techniques shifted to reduce soil disturbance, allowing for occasional grasses and aromatic Mediterranean plants such as Thymus sp., which are supported by VAM fungi. The appearance of Glomus irregulare in the 10-year-old site and Scutellospora coralloidea at the 20-year-old site may represent the slow return of a more mixed VA-and ECM-plant community, typical of more mature truffle beds and Mediterranean open oak woodlands (Belfiori et al, 2012;Maremmani et al, 2003).…”

“…As an agroforestry endeavour, cultivation of black truffles can be economically profitable in marginal farmlands, promoting increased land-use stability, 2 Inquiry into this community began with identification and morpho-typing of approximately 25 frequently observed ectomycorrhizae collected from truffle soils (Donnini & Bencivenga, 1995;Baciarelli-Falini et al, 2006) and has expanded to include 100 species of ECM fungi corresponding to 31 fungal genera (De Miguel et al, 2014). Belfiori et al (2012) observed a negative correlation between the ECM richness and the abundance of T. melanosporum mycorrhizae. The hypothesis that T. melanosporum is a dominating colonizer is supported by evidence for a decrease in the overall soil fungal diversity with the development of the truffle brûlé (Napoli et al, 2010).…”

Diversity, population genetics, and evolution of macrofungi associated with animals

“…The microbial community structures have been found to differ between natural and cultivated truffle habitats, between productive and nonproductive plantations, and between different Tuber species and developmental stages of truffles. Belfiori et al (2012) found that the diversity of ectomycorrhizal species is lower in cultivated plantations than in natural habitats, higher in Tuber brumale -colonized plants than that of T. melanosporum -colonized plants (Belfiori et al 2012), and higher in productive plantations than in the nonproductive ones (De Miguel et al 2014). In the T. magnatum natural habitats, the most abundant fungal species belong to Thelephoraceae, followed by Sebacinaceae, Inocybaceae, and Russulaceae (Murat et al 2005; Leonardi et al 2013).…”