Contributions of Arbuscular Mycorrhizal Fungi to Growth, Biomass and Nutrient Status of Pistachio Seedlings under Saline Conditions

Excessive salt accumulation in soil is a major ecological and agronomical problem, especially in arid and semiarid areas. Excessive soil salinity affects the establishment, development and growth of plants, resulting in major losses of production. A pot experiment was set up to examine the effects of arbuscular mycorrhizal fungus (Glomus etunicatum and Glomus versiforme) and salinity on the growth, pigment concentration, biomass and nutrient acquisition of pistachio (Pistacia vera L.) seedlings. Two-month-old pistachio seedlings colonized by G. etunicatum and G. versiforme were irrigated with 0 and 150 mM NaCl solution for 45 days to induce salt stress. The results showed that salt stress significantly reduced mycorrhizal colonization in pistachio seedlings, and G. versiforme was found to be more colonized than G. etunicatum. Mycorrhizal inoculation, especially G. versiforme, had higher plant growth, biomass and pigment content than non-mycorrhizal under control and salt stress treatments. Shoot Na concentrations were lower in mycorrhizal than in non-mycorrhizal seedlings under given salinity conditions. Total P, K, N, Ca macronutrients and micronutrients decreased with soil salinity in both mycorrhizal and non-mycorrhizal seedlings. These nutrients were higher in AM, especially G. versiforme, than in NM seedlings in control and salt stress treatment. The results suggested that mycorrhizal, especially G. versiforme, pistachio plants exhibited greater efficiency in alleviating salt stress, which resulted in better growth.