Drylands are specific habitats for the growth of xerophyte plants. These lands are vulnerable to numerous threats, and all biotic and abiotic stresses can play essential roles. In 2022, declining symptoms were observed for Haloxylon ammodendron and Astragalus verus in the Alborz, Tehran, and Hamedan provinces. Therefore, this study aimed to characterize fungal communities associated with the decline of H. ammodendron and A. verus in drylands using ITS sequencing. Symptomatic plants were sampled and cultured on PDA media. After fungal purification, DNA extraction was performed, and the DNA in the ITS region was sequenced. The fungal genera identified in this study included Alternaria, Arthrinium, Astragalicola, Biscogniauxia, Chaetomium, Cytospora, Fusarium, Mucor, Neoscytalidium, Paecilomyces, Pithomyces, Preussia, Sordaria, and an undefined genus. Eleven identified genera of fungi were associated with H. ammodendron in dry areas of Tehran and Alborz provinces, while 10 genera were associated with A. verus plants in Hamadan province. The mycobiota profile showed a high relative frequency of fungal genera belonging to the Paecilomyces and Biscogniauxia genera in H. ammodendron plants and the Astragalicola and Chaetomium genera in A. verus plants. Additionally, seven genera of fungi were common to both hosts, while none of the seven other genera were shared by both hosts. Based on these results, Ascomycota comprised a large part of the mycobiota, and a minor part of the mycobiota belonged to Mucoromycota (only in A. verus plants). Our findings confirmed that the presence of the most important pathogenic genera of fungi in H. ammodendron and A. verus plants could be a threat to other dryland plants. This information can be valuable for conservation efforts and developing strategies to mitigate the threats posed by these pathogenic fungi to dryland ecosystems.
alizadeh et al. (Sat,) studied this question.