Document Type : Research Paper
Authors
1
Forests and Rangelands Research Department, Qom Agricultural and Natural Resources Research and Education Center, AREEO, Qom, Iran
2
Department of Forestry, Faculty of Natural Resources Sciences, University of Tehran, Karaj, Iran
3
Research institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
4
Department of Agronomy and Plant breeding, Faculty of Agricultural Sciences, University of Tehran, Karaj, Iran
5
School of Plant Sciences, the University of Arizona, Tucson, Arizona, USA
Abstract
Euphrates poplar (Populus euphratica Oliv.) is a woody species that is naturally distributed in the desert areas of some parts of Asia and Africa. Because of its outstanding features, it is a model plant to study environmental stress tolerance. This research was conducted from 2014 to 2016 in order to study the relationship between performance indices and ion concentrations. The cuttings of 12 ecotypes were collected from different climatic conditions in Iran. Salinity stress was applied using four levels of NaCl (75, 150, 225 and 300 mM) and one control sample (salt-free). The performance indices [diameter and height growth, biomass production; leaf, stem, root and total biomass] showed significant differences in salt levels and ecotypes. The ion concentrations showed significant differences in salt levels (except Ca2+) and varied in different ecotypes. There was no significant difference in salt×ecotype interaction for most of the variables. The ecotypes, treatments, (salt levels) means of performance indices and ion concentrations were separated into different groups. Correlation coefficients showed that the concentration of macronutrients had positive correlations with performance indices, and that salt ions had negative correlations. Correlation coefficients also showed that the ion concentrations had synergistic or antagonistic effects on each other. The results of this study showed that the key mechanisms of salt tolerance in this specie include: exclusion of salt from the root, compartmentalization of Na+ in plant tissue, preventing excessive reduction of K+ absorption resulting in the maintenance of the K+/Na+ balance.
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