Irrigation water source matters: Saline groundwater irrigation lowers date palm root-associated fungal richness and alters their community patterns

Saline groundwater irrigation is predominantly used for date palm (Phoenix dactylifera) cultivation in the arid regions of the Middle East and North Africa without knowing its impact on root-associated fungal (RAF) communities. We investigated the impact of irrigation water sources (freshwater vs. saline groundwater) on date palm RAF diversity, communities, and their assembly processes. Summarily, we show that water chemistry (pH and EC) mainly structures RAF communities, whereas water pH shapes saprotrophic and pathotrophic communities, and the higher abundance of saprotrophic RAF (i.e. Acrocalymma vagum) under saline groundwater irrigation, despite the higher importance of the drift process, indicates their potential role in nutrient cycling and plant growth promotion under saline conditions in arid agroecosystems.