@ARTICLE{, author = {}, title = {Effect of salt stress on morphological and physiological traits of two species of rapeseed (Brassica napus and B. rapa)}, volume = {14}, number = {2}, abstract ={To study the effect of salt stress on morphological and physiological traits of different Brassica species a greenhouse experiment was conducted in Tarbiat Modares University. Eighteen rapeseed cultivars (fifteen cultivars of B. napus and three cultivars of B. rapa), and two levels of soil salinity (2 and 12 dS.m-1) were experimented as factorial arrangement in randomized complete block design with three replications. The total experiment duration was 50 days (time from planting to the end of rosette stage). Results showed that salt stress reduced number of leaf, leaf area, weight of petiole, blade and biomass. However salt increased the water content and relative water content of leaf, but the ratios of blade to petiole weight and phloem to xylem weight. The lowest variation was observed in the relative water content of leaf, whereas the highest variation was in biomass and leaf water content. There was no significant correlation between biomass and number of leaf. Biomass was significantly correlated with the blade area and weight. Salinity decreased the total and chlorophylla and chlorophyllb contents, potassium (K+), ratio of potassium to sodium (K: Na+) in blade and membrane integrity. Salinity increased the concentration of Na+ in blade. Increase in the concentration of Na+ was higher than decrease in the concentration of K+ in blade. Salt stress had no effect on a/b chlorophyll and other plant pigments such as carotenoid, antocyanine and flavonoids. The concentration of proline increased in B. napus and decreased in B. rapa with increasing salinity. No significant correlation was found between proline and biomass in both species. Results of this study demonstrated that B. napus coped better with salt stress than B. rapa in early stages of growth which can be attributed to the amphidiploidy of B. napus. }, URL = {http://agrobreedjournal.ir/article-1-90-en.html}, eprint = {http://agrobreedjournal.ir/article-1-90-en.pdf}, journal = {Iranian Society of Crops and Plant Breeding Sciences}, doi = {}, year = {2012} }