The desert truffle (Terfezia) and other truffles (Tuber) have a significant economic and ecological value and are considered as important fungi in Morocco. Desert truffles are important to combat desertification and enhance soil fertility. As these fungi form a mycorrhizal symbiosis with several specific desert shrubs, it protects the soil from degradation and assists plant growth in the semi- arid and desert areas. The aim of this short paper is to present the different species of desert truffle that exist in Morocco and identify their macroscopic and microscopic characteristics and their host plants as well as their areas of distribution. There are strong analogies between the species found in Morocco with those previously discovered in other countries. Terfezia arenaria, T. leptoderma and Delastria rosea were mainly available in Mamora forest and T. boudieri in Oualidia. Otherwise, the species Picoa juniperi, Terfezia claveryi, Tirmania pinoyi and T. nivea were present in the Oriental regions of Morocco.

The distribution and abundance of the various truffle species are influenced by the climate, soil, and vegetation conditions. The setting of these characteristics is necessary for the potential species’ cultivation. Here, we describe the ecological characteristics of Moroccan truffles and desert truffles and their associations with host plants. We also determine the climate and soil parameters relating to the geographic distribution and fructification of truffles and desert truffles. In contrast to truffles, which are found in sub-humid environments, desert truffles are found in semi-arid and arid regions of Morocco. The dissemination of desert truffles in the Mamora forest and oriental regions of Morocco is typically linked to the presence of Helianthemum sp., whereas the existence of truffles (Tuber spp.) in the Middle Atlas depends on the subsistence of Quercus ilex and Q. faginea. The truffles’ and desert truffles’ fructification depends mainly on the precipitation frequency. Terfezia arenaria and Tuber oligospermum, the two major desert truffles of Mamora forest, require an annual rainfall of 435 mm on average in slightly acidic soil. While the oriental and Highland desert truffles, namely Terfezia boudieri, T. claveryi, and Tirmania spp., require an annual precipitation average of 123 to 267 mm and a high CaCO₃ content. Otherwise, there is Tuber aestivum, localized in humid regions with a rainfall rate of more than 650 mm, and found under calcareous soil rich in organic matter with the presence of potential host plants, such as oaks, cedars, and pines. Our findings open up the possibility of successful cultivation of truffles and desert truffles having an economic interest through understanding their ecological requirements in Morocco.

Helianthemum guttatum Mill and Helianthemum ledifolium are herbaceous Cistacea species, known for their drought tolerance and symbiotic association with desert truffles (Terfezia, Tirmania…). Even if their propagation mainly occurs through seeds. However, germination is limited by...