Septoglomus species dominate the arbuscular mycorrhiza of five crop plants in an arid region of northern Mexico.

Arid zones represent 44% of the world's agricultural land where crops are exposed to stressful conditions, mainly water deficiency and high solar radiation. Under such conditions, arbuscular mycorrhizal fungi (AMF) may improve plant stress resistance by increasing water and nutrient uptake but their diversity and community in dryland agroecosystems remains underexplored. The objective of this study was to investigate the AMF species diversity and community associated with five economically relevant crops (alfalfa, pepper, maize, onion and walnut) grown in an arid zone of northern Mexico. DNA was extracted and PCR-amplified with AMF specific primers from root and rhizosphere soil samples. Libraries were constructed and sequenced using the Illumina MiSeq system; representative sequences were assigned to 30 species in 12 genera. AMF community composition was similar among the crops but significantly different between the roots and the rhizosphere soil. A strong dominance, in terms of DNA sequence read abundance of Septoglomus sp. was found in root samples. On the contrary, in rhizosphere soil Rhizophagus spp. and Funneliformis mosseae were more abundant. Most of the Septoglomus sequences were affiliated to a node in-between the branches of the species S. viscosum and S. titan, indicating an undescribed or uncharacterized highly abundant species in this ecosystem. Describing and understanding plant associated AMF communities in drylands may provide valuable information for future tailored made inocula efforts. [ABSTRACT FROM AUTHOR]