Advancements made in desert truffle mycorrhization of Helianthemum

September 26, 2018

Shifting away from traditional spore driven inoculation of Helianthemum plants with Terfezia claveryi, the desert truffle, may become increasingly popular among the growers of this prized truffle as mycelial inoculation techniques improve.

Fig. 1 Ascocarp of Terfezia claveryi (a), isolated mycelium of T. claveryi in MMN medium (b), mycelium preculture in liquid medium (c), fermentation process in a 5-L stirred tank bioreactor (d), mycorrhizal H. almeriense plants with T. claveryi liquid mycelium 2 months after in vitro inoculation (e), mycorrhizal colonization and Hartig net in stained roots under microscope are marked with black arrows (f, g) (Arenas, et al., 2018)

Shifting away from traditional spore driven inoculation of Helianthemum plants with Terfezia claveryi, the desert truffle, may become increasingly popular among the growers of this prized truffle as mycelial inoculation techniques improve. In a recently published article in the journal Mycorrhiza, “Mycelium of Terfezia claveryi as inoculum source to produce desert truffle mycorrhizal plants,” Arenas, et al. have shown that through alterations to the growth media, mycelial growth of this truffle can be optimized and adapted for in vitro mycorrhization. Demonstrating the ability to colonize the roots of Helianthemum, Arenas, et al. were able to achieve mycorrhization of over 50% on the roots used in their study after a mere two months of development while growing in vitro.

This paper lists contamination such as pathogens and non-target mycorrhizae as reasons to move away from spore-based inoculations. One of the main hurdles which have been largely overcome due to the work found in this paper, is the slow growth this fungi exhibits while maintained in vitro. By determining the limiting and non-limiting factors built into the growth media used in culturing this fungi, Arenas, et al. have been able to significantly improve the biomass produced by the strain of T. claveryi used in this study such that growth may prove to no longer be an issue.

Some further limitations the paper acknowledges are that is it currently not known if this truffle is heterothallic, and therefore identifying and pairing compatible mating types may be required. The work described within this paper can be used to inform similar work by those aiming to move away from spore-based inoculation of cultivated mychorhizal fungi.

Source:

Arenas, F., Navarro-Ródenas, A., Chávez, D., Gutiérrez, A., Pérez-Gilabert , M., & Morte, A. (2018). Mycelium of Terfezia claveryi as inoculum source to produce desert truffle mycorrhizal plants. Mycorrhiza.