Effects of High Salinity on Physiological and Anatomical Indices in the Early Stages of Populus euphratica Growth

The Tarim River and the Heihe River are two most important and largest inland rivers in Western China. Their downstream areas are known as a green corridor covered with lush riparian forests several miles wide. World’s 54% area of Populus euphratica vegetation is spread in this basin and mainly distributed on riverbanks or areas with deep water tables. Salinity is one of the major abiotic stresses limiting plant growth and productivity, particularly in arid land. The effect of abiotic stress on hydraulic traits in riparian plants is highly correlated with plant anatomy viz. fibers, pith membrane.

In this study, the effects of salinity stress on stomatal aperture and density, xylem vessels, the activities of antioxidant enzymes, such as superoxide dismutase (SOD) and peroxidase (POD), and xylem embolism (PLC values) in P. euphratica in the arid ecosystem of China were analyzed. Pot experiment was conducted at different concentrations of salt (50, 100, 150, and 200 mM NaCl) contained in the irrigation water used for 3 months.

The POD activity increased with the increase in the severity of NaCl stress, but SOD activity was varied at different levels of salt. Results indicated that salt treatment reduced stomatal aperture and leaf photosynthetic capacity. However, the significant reduction in the stomatal area, in the length of stomata openings and an increase in stomata density were noticed. Salinity stress affected water transport, which reduced native PLC value, whereas xylem vessel area was also decreased.

The result was published in Russian Journal of Plant Physiology in March 2015.