The effect of environmental factors on growth characteristics, seed germination and essential oils of Ziziphora clinopodioides

In this study, the relationship between altitude, climate and soil characteristics as important and effective factors on the growth characteristics, seed germination and essential oils of Ziziphora clinopodioides were examined. Three habitats of this species with different altitudes were selected in Alborz and Mazandaran provinces. Growth characteristics of Z. clinopodioides bushes in 45 plots located at the three habitats were recorded. Seed of this species collected from three habitats and their viability was determined. Three soil samples were taken from each habitat and some physical and chemical characteristics were measured. Analysis variance results of data showed that there is a significant difference among the three habitats from the viewpoint of growth characteristics, soil features and common combinations of essential oils. The highest seed viability was obtained for Rineh habitat with chilling and scratching seed coat. The most important environmental factors affecting the vegetative characteristics and essential combinations was determined using principal component analysis. The results showed that annual temperature, absolute minimum temperature, maximum temperature of the warmest month, number of frost days, altitude, electrical conductivity, moisture saturation, organic matter and soil texture had the greatest impact on these properties.