Effect of two isolates of Glomus mosseae from saline and non-saline soil and NaCl level on the growth, biochemical indices and mineral composition of three pistachio rootstocks. 1. Growth and biochemical characteristics

Soil salinity is one of the present major problems in the most pistachio growing areas of Iran which influences water and nutrient uptake and results in considerable growth suppression. Vesicular-Arbuscular Mycorrhizal fungi (VAM) have been recognized to reduce the detrimental effects of salinity on plants under saline soil conditions. The aim of the present investigation was to study the effect of two isolates of Glomus mosseae (Gm) recovered from saline and non-saline soil and four NaCl levels (0, 1400, 2800 and 4200 mg/kg of soil) on growth and biochemical characteristics of three pistachio rootstocks (Sarakhs and Qazvini and P. atlantica). In NaCl-treated soil without mycorrhizal fungus, Altanltica and Qazvini had higher shoot and root dry weight, leaf area, stems diameter and height, chlorophyll, proline and total sugar concentrations compared to Sarakhs. Based on the above criteria, Atlantica and Qazvini were found to be tolerant and Sarakhs was sensitive to salinity. The above mentioned criteria were higher in colonized plants by Gm from saline soil (GmS) than non-mycorrhizal plants. Non-saline soil of Gm (GmNS) did not significantly affect these characters. The number of plants survived in mycorrhizal plants at different NaCl levels was greater in non-mycorrhizal plants. In Sarakhs, maximum effect of GmS on growth and biochemical characteristics were at low salinity and at medium levels of salinity in the others two rootstocks. In all rootstocks, the effect of GmS at high NaCl level on the above criteria was reduced and was even less than no NaCl treatment. Also, increasing NaCl level generally caused a reduction of root length colonization of three roortstocks which was only significant in Sarakhs compared to zero NaCl level. Sarakhs showed the highest effects of GmS on the growth and biochemical characteristics. The overall results showed that growth and biochemical characteristics improvement in plants colonized by Gm may be considered as a mechanism of reducing detrimnetal effect of salinity and also to enhance pistachio seedlings tolerance to saline soil conditions.