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Truffle cultivation has drawn more and more attention for its high economic and ecological values in the world. To select symbionts suitable for cultivation purposes, we conducted greenhouse-based mycorrhization trials of two Tuber species (T. formosanum and T. pseudohimalayense) with five broad-leaved tree species (Corylus yunnanensis, Quercus aliena var. acutiserrata, Q. acutissima, Q. robur, Q. variabilis) and one conifer species (Pinus armandii). Axenically germinated seedlings of all tree species were either inoculated, or not, with spore suspensions of these two truffles in the greenhouse. Eight months after inoculation, T. formosanum or T. pseudohimalayense ectomycorrhizae were successfully formed on these six tree species, as evidenced by both morphological and molecular analyses. All selected trees showed good receptivity to mycorrhization by both fungi, with average colonization rates visually estimated at 40-50%. Plant growth, photosynthesis, and nutrient uptake were assessed 2 years after inoculation and were mainly affected by host species. Mycorrhization by both fungi significantly improved P uptake of the hosts, and the interaction between truffle species and host plant species had significant effects on leaf water and leaf K concentrations. In addition, a significantly negative correlation between leaf Ca and leaf C concentration was found across all the seedlings. In addition, mycorrhization had slightly increased plant stem and canopy, but had no significant effects on plant photosynthesis. Overall, these results suggest that the effects of these two Tuber ECMF on plant growth and nutrient acquisition depend on the identity of the host species. Moreover, all selected plant species could be symbiotic partners with either T. pseudohimalayense or T. formosanum for field cultivation purposes., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

We aimed to test whether Tuber melanosporum and native Chinese oak species could form stable mycorrhizal symbioses. Six oak species were all either inoculated or not, with spores of the Périgord black truffle in the greenhouse. Ectomycorrhizal development was monitored for up to 32 months. Seedling growth was assessed 2 years after inoculation. From 6 months after inoculation, Tuber melanosporum ectomycorrhizae were successfully produced on five Quercus species endemic to China, as shown by morphological, anatomical, and molecular analyses. Quercus mongolica and Q. longispica showed high receptivity to mycorrhization by T. melanosporum. The symbioses obtained with these two species and with Quercus senescens were stable for at least 32 months. Averaged over all three oak species, mycorrhization by T. melanosporum significantly enhanced canopy diameter, number of leaves, and mean leaf dimension. In spring 2019, mycorrhization by T. melanosporum accelerated budbreak in Q. mongolica. Quercus fabrei and Q. variabilis formed ectomycorrhizae up to 9 months after inoculation but seedlings died 3 months later, probably because of damage by grazing insects. Quercus pseudosemecarpifolia failed to form ectomycorrhizae. Results suggest that T. melanosporum-mycorrhized Q. mongolica and Q. longispica seedlings could be tested for ascocarp production and increased performance in the field.

Hydnobolites is an ectomycorrhizal fungal genus with hypogeous ascomata in the family Pezizaceae (Pezizales). Molecular analyses of Hydnobolites using both single (ITS) and concatenated gene datasets (ITS-nLSU) showed a total of 223 sequences, including 92 newly gained sequences from Chinese specimens. Phylogenetic results based on these two datasets revealed seven distinct phylogenetic clades. Among them, the ITS phylogenetic tree confirmed the presence of at least 42 phylogenetic species in Hydnobolites. Combined the morphological observations with molecular analyses, five new species of Hydnobolites translucidus sp. nov., H. subrufus sp. nov., H. lini sp. nov., H. sichuanensis sp. nov. and H. tenuiperidius sp. nov., and one new record species of H. cerebriformis Tul., were illustrated from Southwest China. Macro- and micro-morphological analyses of ascomata revealed a few, but diagnostic differences between the H. cerebriformis complex, while the similarities of the ITS sequences ranged from 94.4 to 97.2% resulting in well-supported clades. [ABSTRACT FROM AUTHOR]