Investigation of Some Physiological Traits in Dracocephalum Moldavica L. Ecotypes under Salt Stress Condition

Moldavian balm (Dracocephalum moldavica L.) is a medicinal plant belonging to the Lamiaceae family which uses as stomachic, sedative and healing of wound. Non-uniform establishment of medicinal plants in arid zones soil especially under abiotic stresses such as salinity is the most important problems in cropping and developing of these plants.

In order to study the effect of salinity stress on some physiological traits related to salinity stress of 14 ecotypes of Dracocephalum moldavica L., an experiment were carried out using randomized complete block design with four replications under normal and salinity stress conditions. Two conditions in this experiment were carried out using normal water with 2.3 dS.m-1 and saline water with 14 dS.m-1 electrical conductivity. Proline concentration, chlorophyll a and b concentration, carotenoid concentration, relative water content, sodium and potassium concentration and sodium to potassium ratio were measured in this research.

The results of combined analysis of variance revealed that salinity stress had significant (p<0.01) effect on concentration of chlorophyll a and b, relative water content, concentration of sodium and potassium and sodium to potassium ratio. Stress × ecotype interaction was significant (p<0.01) in all the studied traits except proline concentration. Combined analysis of variance showed that the differences among ecotypes were significant (p<0.01) in all the studied traits. Salinity stress led to a significant decrease in concentration of chlorophyll a and b, concentration of potassium and relative water content and a significant increase in concentration of sodium and sodium to potassium ratio. Results of this research showed that Faridan, Isfahan and Maragheh had more concentration of potassium under normal and salinity stress conditions and so these ecotypes could be suggested for cultivation under both conditions.

Mean comparison of data for studied ecotypes showed that Faridan, Isfahan and Maragheh ecotypes could be suggested for cultivation under both conditions.