Molecular identification of Tuber magnatum ectomycorrhizae in the field

Abstract

Tuber ectomycorrhizae in a Tuber magnatum "truffière", located in Central Italy, were studied using molecular methods. Specifically, RFLP-ITS analyses, ITS sequencing and specific probes hybridization were used to identify 335 Tuber-like ectomycorrhizal morphotypes. Molecular identification was possible even when distinct morphological characteristics were lacking. For the first time, T. magnatum ectomycorrhizae and other coexisting Tuber species collected in the field were analysed using molecular tools for unambiguous identification. Although the "truffière" under investigation yields good harvests of T. magnatum fruiting bodies, the percentage of T. magnatum ectomycorrhizae found was very low (less than 4.4% of the 335 root tips analysed), whereas the percentages of Tuber maculatum and Tuber rufum were considerably higher (48.9% and 19.0%, respectively).

Soil analysis reveals the presence of an extended mycelial network in a Tuber magnatum truffle-ground

“…However, our finding is in contrast to the distribution of H. cylindrosporum mycelium that was not found >50 cm away from a fruiting body (Guidot et al, 2002). Our survey in the truffle-ground shows that the number of T. magnatum-positive soils and that of fruiting bodies harvested are much greater than that of mycorrhizas Bertini et al, 2006) and that there is no direct linkage among belowground mycelium, mycorrhizas and fruiting bodies. On the basis of the current literature, the analyses that consider all the steps of ectomycorrhizal fungi life cycle as the parameter for their distribution are still limited.…”

New evidence for nitrogen fixation within the Italian white truffle Tuber magnatum

“…T. magnatum is an hypogeous fungus and lives in symbiosis with host plant roots to accomplish its life cycle which involves a first phase of growth as filamentous mycelium, a second phase of symbiotic TM1 cl5 mRNA, TM1 cl6 mRNA, TM1 cl8 mRNA, TM 1 cl9 mRNA, TM1 cl10 mRNA TM2 cl1, TM2 cl2, TM2 cl3, TM2 cl4 / TM2 cl3 mRNA, TM2 cl4 mRNA TM1 cl7, TM1 cl8, TM1 cl9, TM1 TM7 cl4 TM7 cl3, TM3 cl3, TM3 cl4 TM7 cl1, TM7 cl2, TM8 cl2 / TM8 cl1 mRNA TM5 cl2 TM6 cl2, TM1 cl4, TM1 cl1, TM1 cl3, TM1 cl2, TM1 cl5, TM1 cl6, TM3 cl2, TM9 cl4, TM9 cl3, TM9 cl1,TM9 association as ectomycorrhizae and finally the organization of hypogeous fruiting body with asci and ascospores (Hall et al 1998). Although the saprobic strategy of ascocarp development is debated (Zeller et al 2008), T. magnatum ascomata can grow in soil supported by very low numbers of mycorrhizas (Bertini et al 2006). Moreover, direct linkages among belowground mycelium, mycorrhizas and fruiting bodies in T. magnatum truffle-ground are absent (Zampieri et al 2010).…”

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

“…Markers based on the internal transcribed spacer (ITS) region of the rDNA locus are now broadly used to study ECMs in various environments (Horton & Bruns, ). For example, molecular typing has been recently used to study the EM communities in T. melanosporum and Tuber aestivum orchards (Baciarelli Falini et al ., ; Pruett et al ., ; Benucci et al ., ) and in natural Tuber magnatum and Tuber borchii truffle grounds (Murat et al ., ; Bertini et al ., ; Iotti et al ., ). Napoli et al .…”