Mycorrhization of pecan (Carya illinoinensis) with black truffles: Tuber melanosporum and Tuber brumale

Abstract

Pecan, Carya illinoinensis, is an economically important nut producing tree that can establish ectomycorrhizal symbiosis with a high diversity of fungi. In the southern USA, truffles (Tuber spp.) sometimes fruit prolifically in cultivated pecan orchards and regularly associate with pecan roots as ectomycorrhizae (ECMs). It has been demonstrated that some valuable European truffle species (e.g., Tuber borchii and Tuber aestivum) can form ECMs with pecan seedlings in nursery conditions. Thus, pecan may represent an attractive alternative host to forest trees for truffle growers given the potential for co-cropping truffles and pecans. To further explore the capacity of pecan to host truffle symbionts, pecan seedlings were inoculated with species of black truffles that are economically important in Europe, T. melanosporum and T. brumale. Ectomycorrhizae were characterized molecularly and their morphology was described in detail. Mycorrhization rates on pecan roots were assessed over a 2-year period. Tuber melanosporum and T. brumale produced well-formed ECMs with a level of root colonization in the first year of 37.3 and 34.5%, respectively. After 24 months, the level of mycorrhization increased for T. brumale (49.4%) and decreased for T. melanosporum (10.5%) inversely to that of non-target ECM greenhouse contaminants (e.g., Sphaerosporella brunnea, Trichophaea woolhopeia, Pulvinula constellatio). To assess whether mating types segregated in T. melanosporum as been reported for other host species, we amplified the mating-type locus from single T. melanosporum ECM belonging to different seedlings over a 2-year period. The two mating idiomorphs were nearly equally represented along the 2-year time span: MAT 1-1-1 decreased from 59.4% in the first year to 48.5% in the second year after inoculation. Data reported in this study add to knowledge on the mycorrhization of pecan trees with commercial truffles and has application to truffle and nut co-cropping systems.

Chinese Black Truffle (Tuber indicum) Alters the Ectomycorrhizosphere and Endoectomycosphere Microbiome and Metabolic Profiles of the Host Tree Quercus aliena

“…The ectomycorrhizal synthesis is crucial for efficient cultivation of truffles ( Iotti et al, 2016 ; Marozzi et al, 2017 ). In the field, a variety of factors have been found to affect the microbial communities associated with truffle ectomycorrhizae, such as the host species, the age of the plantation, the surrounding environment and the management practices ( Leonardi et al, 2013 ; Fu et al, 2016 ).…”

“…is an ectomycorrhizal fungus, which does not produce fruiting bodies without symbiotic association with its host plants. Truffles can form a symbiotic relationship with several genera of trees, including Abies , Corylus , Pinus , and Quercus ( Zitouni-Haouar et al, 2014 ; Marozzi et al, 2017 ). The black truffle ( Tuber melanosporum ) and the white truffle ( T. magnatum ) have been highly valued in the European market because of their unique flavors ( Vita et al, 2015 ; Payen et al, 2016 ).…”

Tuber indicum shapes the microbial communities of ectomycorhizosphere soil and ectomycorrhizae of an indigenous tree (Pinus armandii)

“…Successful ectomycorrhizal synthesis is the basis of efficient cultivation [1, 4, 5]. In truffle orchards, several factors have been found to affect the ectomycorrhizal communities, such as the age of the plantation, the host species, productivity, the surrounding environment and management [20].…”

Mycorrhizal associations of the exotic hickory trees, Carya laciniosa and Carya cordiformis, grown in Kórnik Arboretum in Poland

“…The genus Carya belongs to the Juglandaceae family, which is characterized by species that associate with both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi (Wang and Qiu 2006 ; Taber et al 1982 ), except for Juglans nigra , which forms only arbuscular mycorrhizae (Bainard et al 2011 ; Brundrett et al 1990 ; Wang and Qiu 2006 ). Information about the EM fungal assemblages of hickory trees is very limited, and restricted to the pecan hickory ( C. illinoinensis ) (Bonito et al 2011 ; Ge et al 2017 ; Marozzi et al 2017 ), which is economically important to the pecan nut industry (Thompson and Conner 2012 ), but, due to its very low frost resistance, has not been successfully acclimatized in the temperate zone of Europe. The AM fungi of Carya species are even less well documented, although some information about the arbuscular mycorrhizae of pecan roots in natural, semiarid environments has been provided (Taber et al 1982 ).…”