Three new species of arbuscular mycorrhizal fungi discovered at one location in a desert of Oman: Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus

Abstract

Three new species of arbuscular mycorrhizal (AM) fungi (Glomeromycota) were isolated from soil samples collected from a hyperarid sandy plain of South Arabia. Morphological characteristics of the spores clearly differentiated them from closely related AM species. Molecular analyses were performed on rDNA sequences obtained from single spores including a ~1700 bp region comprising partial SSU, ITS, partial LSU and the ~600 bp ITS region only. The phylogenetic trees based on these regions showed that the three species belong to well described genera but are clearly distinct from known species. Consequently, we describe them here as Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus spp. nov. D. omaniana and R. arabicus were isolated from the native, arid habitat, while S. nakheelum was isolated from a nearby irrigated date palm plantation. The discovery of three new species of AM fungi from this location suggests that a number of additional undescribed AM taxa may be present in such desert ecosystems. Further work to understand the diversity and functional significance of these new AM taxa may offer new opportunities for conservation, re-vegetation, and sustainable agriculture in extremely arid environments.

• arbuscular mycorrhizal fungi
• Glomeromycota
• taxonomy
• molecular phylogeny
• arid ecosystem
• desert
• Arabian Peninsula
• Oman

Acknowledgments

We thank Paola Bonfante and her team (University of Torino) for their supportive role during the initiation of the AM fungal diversity studies in southern Arabia; Ahmad Al-Bakri, the director general of Agricultural and Livestock Research of Oman’s Ministry of Agriculture and Fisheries for providing formal and logistical support; Hamood Al-Hashmi for his assistance during the sampling trips; Annette Patzelt (Oman Botanic Garden) for plant identification. The study was financed by complementary grants from Oman’s Ministry of Agriculture and Fisheries, the University of Basel, the Polish National Centre of Science (grants Nos. N N304 061739 and DEC–2012/05/B/NZ8/00498) and the Swiss National Science Foundation (grant No. 130794 to A.W.), which are gratefully acknowledged.