Physiological investigation of arbuscular mycorrhizal fungi-mediated salt tolerance in persimmon (Diospyros kaki) seedlings.

INTRODUCTION

Climate change has increased the frequency of drought periods in the Mediterranean basin, including the Çukurova region, and is projected to exacerbate both drought stress and soil salinization in future agricultural systems. Arbuscular mycorrhizal fungi (AMF) are known to enhance plant growth and alleviate abiotic stress, yet their potential to improve salt tolerance in Diospyros kaki, a species considered sensitive to salinity, remains underexplored.

METHODS

This study, evaluated the effects of two AMF species, Entrophospora etunicatum and Glomus clarum, on growth parameters, chlorophyll content, photosystem II efficiency (Fv'/Fm'), and leaf and root concentrations of K+, P, Ca2+, Na+, and Cl- in D. kaki seedlings exposed to five NaCl concentrations (0, 50, 75, 100, and 150 mM).

RESULTS AND DISCUSSION: Both AMF species, particularly E. etunicatum, significantly improved plant growth, chlorophyll content, and Fv'/Fm' ratio under saline conditions. Although salt stress alone markedly reduced vegetative growth, the salt × mycorrhiza interaction was not statistically significant for growth parameters, suggesting that AMF-mediated growth promotion occurred independently of salinity level. However, for most mineral nutrients, mycorrhizal inoculation significantly increased tissue concentrations, and the salt × mycorrhiza interaction was statistically significant, indicating that AMF enhanced tissue nutrient concentration specifically under salt stress. These findings support Sustainable Development Goals 2 (Zero Hunger) and 13 (Climate Action) by offering a biological strategy to sustain persimmon production in salinizing environments.