Diversity of Arbuscular Mycorrhizal Fungi in the Rhizosphere of Argania spinosa in Morocco

Abstract

Despite the importance of arbuscular mycorrhizal fungi (AMF) within forest and agroecosystems, few data are available about how AMF communities are structured in the root zone of the argan tree. Some studies have characterized endomycorrhizal fungi population occurring in rhizosphere soils of argan trees grown in southwest of Morocco, numerous sites in this area harbored unexplored communities. The endomy-corrhizae diversity of rhizosphere soils collected from 15 argan forest stands located in Lakhssas, Smimou, Ait Baha, Tamanar, Essaouira, Taroudant (Elkodya), Irherm, Guelmim, Imsouane, Anzi, Tiznit, Taghazoute, Ait Melloul, Bouizakarne, and Oulad Teima have revealed the presence of different AMF communities sharing some species but dissimilar AMF community compositions are noted according to sampling time and site. Additionally, the diverse AMF structures detected such as vesicles, arbuscules and hyphae reflect implicitly the germination of AMF propagules in the rhizospheric area of the Argan tree. The pre-evaluation of AMF in the soil through spores' density can indicate AMF community dynamics, signaling either the adaptability of mycorrhi-zal symbionts to the local conditions or its decline. In total, 39 morphotypes of endo-mycorrhizal fungal spores were identified and described, representing seven genera: Glomus (15 species), Scutellospora (3 species), Entrophospora (4 species), Pacispora (2 species), Gigaspora (4 species), Acaulospora (10 species), and Ambispora (1 species). The genus Glomus has a wide occurrence and had the largest number of species. This chapter gives a great overview of the mycorrhizal status of argan trees in their natural habitats of the main Moroccan argan forests.