Effect of Salt Stress on Some Physiological Attributes of Nerium oleander

Salinity is a widespread problem and a limiting factor on the development of urban landscape in arid regions. Due to lack of good quality water in these areas, there is a noticeable to use of low quality water for irrigation of plants. In this regard, introduction of salt tolerant species for using in urban landscape is necessary. In order to investigate the effects of five levels of irrigation water salinity, including: 0.4, 3, 6, 9 and 12 dS/m-1 on some physiological attributes of Nerium oleander under greenhouse condition, an experimental was conducted based on randomized complete block design with three replicates. The results showed that the all salinity levels caused significant increase of sodium concentration and reduction of potassium in root in comparison with the control treatment. The amount of sodium in leaves of Nerium oleander only at the 12 dSm-1 concentration level had a significant difference with control. On the other hand the potassium concentration in Nerium oleander leaves was not affected by the salinity. Also the leaf Proline concentration was increased with increasing salinity, but there was no significant difference in the amounts of soluble sugars and chlorophyll between different treatments. So, it seems Nerium oleander by the Proline aggregation and also absorption and holding the sodium and chlorine in the roots and preventing their translocation to the leaves, can tolerate salt stress.