An investigation by the University of Murcia, funded by the Seneca Foundation, achieves great advances on the controlled cultivation of the desert truffle
Knowing the potential distribution of the desert truffle will allow us to know the abiotic and biotic factors that delimit it and identify new areas, until now unproductive for other traditional crops, that could be ideal for this rainfed crop. This will contribute to improving the socio-economic situation of these areas and to lead the turmiculture at the national and international level.
In addition, the growing demand for mycorrhizal plant with desert truffle requires exploring new strategies to improve the mycelial growth of these truffles and the use of it as a new, more stable and controlled source of inoculum. This greater control over the growth of the mycelium of ‘T. claveryi ‘will allow scientists to further address basic research trials on the biology of these fungi.
With these objectives on the table, Asunción Morte, professor of Plant Biology at the University of Murcia, leads the project ‘Ecophysiology of desert truffles II: potential distribution, biodiversity and activation of mycelial growth’ financed by the Seneca Foundation – Regional Agency of Science and Technology.
They have been able to typify ‘Terfeziafanfani’, which historically and incomprehensibly had been confused and synonymised with ‘Terfezialeptoderma’
“The project consists, on the one hand, in studying the distribution and biodiversity of mycorrhizal hypogeal fungi known as ‘desert truffles or turmas’. Turmas are considered a natural resource in the Region of Murcia, of high edible value. On the other hand, it aims to know the factors that affect the growth of the turma mycelium (‘Terfeziaclaveryi’), for a sustainable and effective production of mycorrhized plant with this fungus in the nursery “, explains Morte who, in recent years, has become one of the benchmarks in research on this fungus worldwide.
The professor of Plant Biology at the University of Murcia Asunción Morte. /
The objective of the study is, on the one hand, to know the biodiversity of desert truffles, describing new species, clarifying their phylogenetic relationships and seeing what factors affect their distribution (types of soil, symbiotic plants, climate, etc.). On the other hand, identify the factors that affect the growth of the mycelium of ‘Terfeziaclaveryi’, “to help us make its symbiosis with the plant more effective.”
The UMU group has built a series of climate models that explain the interannual variability in turma production
This researcher, who heads the Mycology-Mycorrhiza-Plant Biotechnology group at the University of Murcia, points out as the starting hypothesis “that there are more species of hypogeal fungi than previously thought since desert truffles have a restricted distribution due to its hypogeal fruiting (limited dispersal) and its symbiotic nature (co-dispersion with the host plant and necessary microhabitat), so that ‘not everything is everywhere and it is the environment that selects’. In addition, the mycelium of the fungus shows slow growth, which could be modulated by radical exudates, certain associated bacteria and internal regulation mechanisms such as the post-transcriptional maturation of its rRNA ».
The project, which is in a very advanced phase, has allowed them to advance a lot in the molecular identification of hypogeal fungal species, which has given them the opportunity to typify ‘Terfeziafani’, “which historically and incomprehensibly had been confused and synonymous with ‘Terfezialeptoderma’, and clarify the existing confusion in the species’ Terfeziatrappei ‘, which we have become synonymy as it is’ T. fanfani ‘when examining the type material ”, according to Asunción Morte. Furthermore, “we have described a new species, ‘Terfeziadunensis’, from coastal dune areas and associated with ‘Halimiumhalimifolium’ and ‘Cistussalvifolius’ and two new species of ‘Tuber, Tuberbuendiae’ and ‘Tuberalcaracense'”, adds Morte. These results have led to the publication of four scientific articles in high-impact specialized journals.
Several specimens of truffle
On the other hand, this group of researchers from the University of Murcia has built a series of climate models to explain the interannual variability in the production of turmas. Thanks to the data obtained from the annual production of turms during 15 years and to the variety of climatic data collected, correlations of nine climatic variables have been calculated. “Thus, we have determined that there is a period of time during the autumn where the rains, although they do not have to be abundant, are essential. During winter, the most limiting agroclimatic parameter for production is the water potential of the soil and during spring abundant rains are necessary and the vapor pressure deficit is low. We have observed that the amount of autumn rains can be modulated as a function of the aridity index (quotient between rain and evapotranspiration) of the moment ”, explains the person in charge of the project.
Likewise, through the sequencing of its genome in collaboration with the JointGenomeInstitute, of the United States Department of Energy, and the INRA-Nancy, they have discovered that the truffle ‘T. claveryi ‘is heterothalic, meaning that individuals carry one of two versions of the MAT locus, with genes MAT1-1 or MAT1-2 that regulate the production of sex-specific pheromones. Asunción Morte assures that the discovery leads us to conclude that it would be necessary to ensure in advance that strains or individuals of both sexes are introduced, during the production of mycorrhized plant with mycelium and in the plantations, so that the truffle is later formed, which is the result of sexual reproduction.
Recently, they have also sent to publish, to the journal ‘EnvironmentalMicorbiology’, a metagenomics study on populations of fungi that characterize soils and roots of truffle producing areas and non-producing areas within a desert truffle plantation. “We have evaluated the positive and negative effects of the composition of the fungal community and its life strategies in the production of turmas and some specific microorganisms have been correlated with the productive areas”, says Morte.
In the scientific project, financed within the framework of the Regional Program for the Promotion of Scientific and Technical Research, Action Plan 2018, of the Seneca Foundation; Antonetta Mello, researcher at the Istituto per la Protezione Sostenibiledelle Piante (IPSP) and the CNR (Consiglio Nazionale delle Ricerche) of Turin (Italy) participates.