Influence of arbuscular mycorrhizae on biomass and root morphology of selected strawberry cultivars under salt stress

To investigate the influence of arbuscular mycorrhizal fungi (AMF) on biomass and root morphology, a greenhouse experiment was conducted using three elite strawberry (Fragaria x ananassa Duch.) cultivars ('Kent', 'Jewel', and 'Saint-Pierre'). They were subjected to three NaCl levels (0, 30, and 60 mmol/L) and were inoculated and noninoculated (control) with AMF Glomus irregulare. The presence of AMF significantly changed root morphology and increased root-length percentages of medium (0.5 mm < root diameter phi <= 1.5 mm) and coarse (phi > 1.5 mm) roots, shoot and root tissue biomass, root to shoot ratio (R/S ratio), and specific root length (SRL), regardless of cultivar and salinity. In contrast, salt alone changed root morphology and decreased shoot and root tissue biomass, R/S ratio, and SRL. The AMF colonization rates were reduced linearly and significantly with increasing salinity levels. Cultivars responded differently to AMF than to salt stress. 'Saint-Pierre' seemed to be the most tolerant cultivar to salinity, while 'Kent' was the most sensitive. Consequently, AMF symbiosis highly enhanced salt tolerance of strawberry plants, which confirmed the potential use of mycorrhizal biotechnology in sustainable horticulture in arid areas.