To investigate the influence of arbuscular mycorrhizal fungi (AMF) on biomass and root morphology, a greenhouse experiment was conducted using three elite strawberry (Fragaria × 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 rootlength percentages of medium (0.5 mm < root diameter 4 ≤ 1.5 mm) and coarse (4 > 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.Résumé : Afin d'examiner l'influence des champignons mycorhiziens arbusculaires (CMA) sur la biomasse et la morphologie des racines, les auteurs ont conduit une expérience en serres, en utilisant trois cultivars élites de fraisier (Fragaria × ananassa Duch.) ('Kent', 'Jewel', et 'St-Pierre'). Ils les ont soumis à trois concentrations de NaCl (0, 30, et 60 mmol/L), avec ou sans (témoin) inoculation, avec le CMA Glomus irregulare. La présence du CMA a modifié significativement la morphologie racinaire et a augmenté les pourcentages des longueurs des racines moyennes (0,5 mm < diamètre racinaire 4 ≤ 1,5 mm) et grosses (4 >1,5 mm), la biomasse des tissus caulinaires et racinaires, le rapport racine tige (rapport R/S) et la longueur spécifique des racines (LSR), indépendamment du cultivar ou de la salinité. Au contraire, le sel pris isolément a également modifié la morphologie racinaire et diminué la biomasse des tissus caulinaires et racinaires, le rapport R/S et la LSR. L'augmentation de la salinité a réduit linéairement et significativement la colonisation par le CMA. Le cultivar 'StPierre' apparaît comme le plus tolérant à la salinité et le cv 'Kent' comme le plus sensible. On conclut que la symbiose CMA augmente fortement la tolérance à la salinité chez les plants de fraisiers, ce qui confirme le potentiel de la biotechnologie mycorhizienne pour l'horticulture en régions arides.

Sinclair, G., Charest, C., Dalpé, Y. and Khanizadeh, S. 2013. Influence of arbuscular mycorrhizal fungi and a root endophyte on the biomass and root morphology of selected strawberry cultivars under salt conditions. Can. J. Plant Sci. 93: 997–999. The influence of four arbuscular mycorrhizal fungi (AMF) (Glomus arenarium, G. caledonium, G. irregulare, and G. mosseae) and a root endophyte species (Piriformospora indica – Sebacinales) was investigated on four “day-neutral” strawberry (Fragaria×ananassa Duch.) cultivars (Albion, Charlotte, Mara des Bois, and Seascape) for their tolerance to salt stress. Fungal symbiosis tended to benefit strawberry plants in their tolerance to salinity, confirming the potential use of mycorrhizal biotechnology in horticulture in arid areas.