Evaluation of Yield and some Agronomical Traits in Dracocephalum Moldavica L. Ecotypes under Drought Stress Condition

Moldavian balm (Dracocephalum moldavica L.) is a medicinal plant belongs to the Lamiaceae family, which is used as stomachic, sedative and healing of wound. Drought stress is one of the most important factors limiting the growth and production of crops and affects on plants at different levels. In order to study the effect of drought stress on some agronomical traits of 14 ecotypes of Dracocephalum moldavica L. and their classification, two experiments (under normal and drought stress conditions, 120 mm evaporation from evaporation pan) was carried out using randomized complete block design with four replications. The traits of shoot fresh and dry weight, plant height, number of auxiliary shoots, leaf length and width, stem diameter, length of biggest internode, essential oil content and yield were measured in this research. The results of combined analysis of variance revealed that drought stress had significant effect on all the studied traits except leaf width and length of biggest internode. Drought stress led to a significant decrease in shoot fresh and dry weight, plant height, number of auxiliary shoots, leaf length and stem diameter and a significant increase in essential oil content and yield. Also there were significant differences (p<0.01) among ecotypes in all the studied traits and stress × ecotype was significant for fresh and dry weight and length of biggest internode. Faridan, Garmsar, Khomeinishahr and Urmia ecotypes had better performance based on the most studied traits. Studied ecotypes under normal and drought stress conditions were classified in three groups using cluster analysis based on Ward method and using Eucilidian distance. Faridan, Garmsar, Khomeinishahr and Urmia ecotypes are suggested as drought tolerant ecotypes based on cluster analysis using all studied traits.