Effect of salinity stress on some morphological and biochemical characteristics of three bread wheat (Trticum aestivum L.) genotypes

Salinity is going to become a serious problem in different regions of the world. The saline area is three times larger than lands used for agriculture. Therefore in order to evaluate the effect of salinity on some biochemical and morphological indices of wheat genotypes, a factorial experiment was conducted based on completely randomized design with three replications under hydroponic cultivation conditions. Treatments were two salinity levels (0 dS m-1 (control) and 6 dS m-1) and three wheat genotypes including Tabasi and two mutant lines (T-67-60, T-65-7-1). First, seeds of mutant line, T-67-60 and T-65-7-1 and Tabasi were sterilized to have seedlings free of contaminations. Then, the seeds were placed on wet filter papers in the petri dishes and were placed in an incubator set at 24±1 °C under dark conditions for 3 days. Then seedlings were exposed to salinity and control treatments in Yoshida fluid using hydroponic method. Shoot and root fresh and dry weight, as well as root and shoot length as morphological traits and ascorbic acid, lipoxygenase enzyme (LOX), chlorophyll and TBARM amount as biochemical traits were measured. Results showed that salinity stress had adverse effects on plant growth. LOX, TBARM and chlorophyll level showed significant differences in the studied genotypes under the salinity conditions. Tabasi showed the greatest variations of LOX and TBARM content while the lowest amounts belonged to line T-67-60. Regard to negative correlation between TBARM, LOX and chlorophyll level with salinity tolerance; it seems that T-67-60 mutant line had the highest tolerance compared to the other genotypes.