Interactions between arbuscular mycorrhizal fungus and indigenous compost improve salt stress tolerance in wheat (Triticum durum)

Abstract

Salinity is one of the most harmful abiotic stresses that affect wheat development and metabolism. The main objective of this study was to evaluate the potential effects of biostimulants/biofertilizers as an environment-friendly practice for improving wheat tolerance to salinity. A greenhouse experiment was conducted on a durum wheat variety: Carioca. The wheat seedlings were treated with a pure strain of arbuscular mycorrhizal fungus (M; Rhizoglomus irregulare) and /or compost (C; made from olive pomace with olive mill wastewater under non-saline, medium and high saline (100 and 200 mM NaCl) conditions. The results showed that C application significantly decreased mycorrhizal infection. Salinity reduced growth, physiological functioning, and biochemical processes. However, selected biostimulants/biofertilizers application, especially C alone, mitigated the negative effects of salinity by improving wheat shoot dry weight (65%), root dry weight (22%), phosphorus uptake (544%), and stomatal conductance (180%) than control under 200 mM NaCl. In addition, C application alone and/or M treatments improved osmotic adjustment and antioxidant system, maintained a higher stem water potential, reduced malondialdehyde and hydrogen peroxide content and increased glomalin secretion in soil. These results showed that compost and/ or Rhizoglomus irregulare could mediate salt tolerance and enhance wheat production in degraded areas.