The Moldavian balm (Dracocephalum moldavica L.), is an herbaceous essential oil producing and medicinal plant from Lamiaceae family (Dastmalchi et al., 2007). Due to its strong effects on the gastrointestinal system and other parts of the body, D. moldavica has traditionally been used for treatment of some diseases e.g. stomach and liver disorders in folk medicine. Recently published reports have buttressed its sedative capacity, tranquilizer remedy (Martinez-Vazquez et al, 2012) and anti-Helicobacter pylori activity (Najafi et al, 2008). The present study was carried out to assess the genetic diversity in Iranian landraces (cultivated populations) of Moldavian balm based on some horticultural traits and essential oil characteristics and to find the correlations between them. Seeds of seven populations were provided from different areas of NorthWestern Iran, Included: West Azerbaijan province (Naghadeh, Keshtiban, Topragh Ghalee, and Baghchajogh) and East Azerbaijan province (Hokm Abad, Jahangir and Shiraz valley) and cultivated in the field conditions of Hamadan province. Sixteen horticultural traits were evaluated. Essential oils were extracted from the aerial parts using Clevenger and were analysed by Gas Chromatography-Mass Spectrometry (GC–MS). Based on the results, the landraces from Shiraz valley presented remarkably high mean values for plant height, number of nodes per stem and leaf length. The oil content in landraces varied from 0.03 to 0.12% (w/w). Among the tested D. moldavica landraces, Hokm Abad showed the highest essential oil content (0.12%). On the whole, 41 compounds were identified in essential oils. The dominant constituent for all landraces was Geranyl acetate (19.8%-45.5%) with an exception of Naghadeh (Geranial: 23.82%). The considerable correlations were found among some horticultural and phytochemical traits. According to the Pearson coefficients analysis, branch length was confirmed to be positively correlated (r = 0.559 and 0.594) to Gera
