Can an indigenous consortium of arbuscular mycorrhizae effectively mitigate drought stress in argan trees (Argania spinosa L. Skeels) by modulating mineral nutrition and phosphatase activities?

Abstract

• The effectiveness of a multispecies association of native mycorrhizal fungus on growth and mineral nutrition in argan trees under drought stress conditions. • `Rhizargan' enhanced the resistance of argan plants to drought stress by altering mineral absorption and phosphatase secretion. • Mycorrhization with `Rhizargan' could be an effective agronomic practice for argan trees in any silvicultural program under dry conditions. Climate change-induced drought had hampered the growth and production of argan trees in their semi-arid and arid biogeographic areas. The purpose of this study was to determine the effects of a multispecies association of native mycorrhizal fungus `Rhizargan' on argan trees growth, mineral nutrition, and phosphatase activities under drought stress conditions. The study focused on two distinct argan ecotypes (Admine and Lakhsas), the performance of argan seedlings inoculated with the `Rhizargan' was observed for twelve months and compared to those inoculated with a pure marketed strain of Rhizophagus irregularis under two levels of drought stress (60 ad 30% field capacity). Regardless of drought stress treatment, `Rhizargan' inoculation considerably enhanced the concentrations of phosphorus, potassium, calcium, magnesium, and sodium in the rhizosphere, roots, and leaves, as well as plant growth, especially in Lakhsas ecotype, than Rhizophagus irregularis ' inoculation. Under severe drought stress, `Rhizargan' significantly increased P content, in Lakhsas, by 172.4, 89.0, and 16.7% in leaves, roots, and rhizosphere, respectively, when compared to Rhizophagus irregularis . Our findings suggest that mycorrhization with `Rhizargan' might be an effective agronomic approach for argan trees in any silvicultural program under dry conditions.