Evaluation of Salinity Tolerance of Some Selected Provenances of Populus Euphratica Oliv in Field Conditions

In arid and semi-arid areas, due to the existence of areas with low quality of water and soil, identification of wood species tolerant to salinity is very important. Therefore, this research aimed to identify provenances of Populus euphratica Oliv tolerant to salinity in comparison with the native provenances of Yazd Province, using a split plot experiment based on randomized complete block design (RCBD). Variables included the main factor i.e. salinity at 4 levels, and the secondary factor of Populus euphratica Oliv provenances at 7 levels. The study was performed with 3 replications during 2023-2024 at Hosein Abad Station of the National Salinity Research Center. Irrigation water salinity levels included (2.8, 6, 10 and 14 dS/m) and the provenances included 1) Isfahan, 2) Manjil, 3) Yazd-1, 4) Yazd-2, 5) Garmsar, 6) Garekhlar, and 7) Kerman. The results showed that provenance and salinity level affected the morphological and physiological traits and the concentration of nutrient elements. All the studied provenances tolerated salinity level of 6 dS/m, but with increase in salinity, all the growth characteristics in some of the studied provenances decreased significantly. At 10 and 14 dS/m, total height, total diameter, breast-high diameter, and their increase during the growing season, necrosis percentage and relative water content of leaves in the provenances of Kerman, Manjil and Garmsar significantly decreased compared to the control trees. However, sodium content, sodium to potassium ratio and relative ion leakage of leaves increased significantly compared to the control. A significant decrease in the investigated growth traits was observed in Yazd 1 and Garekhlar provenances only at the salinity level of 14 dS/m compared to the control. These results indicate that the provenances of Yazd-1 and Garekhlar were able to tolerate salinity of 10 dS/m by maintaining its growth characteristics and increasing potassium uptake against sodium. After them, Yazd-2 and Isfahan provenances showed relatively good tolerance to salinity. On the other hand, Kerman, Garmsar and Manjil were recognized as the most sensitive provenances to salinity stress. To select the best provenance for salinity tolerance, it is recommended to study the quality of wood and yield in different locations.