Effect of Drought Stress on some of the Biochemical Characteristics of Three Achillea Populations (Achillea vermicularis)

The experiment was conducted in the form of a randomized completely block design with three replications. The main pots were kept under irrigation (at 20%, 40% and 70% of field capacity along with a well watered control). The sub-pots contained three Achillea vermicularis populations (Kahak, Khalkhal and Semnan). The results showed that drought stress had significant effects on photosynthetic pigments, proline, soluble sugar contents and peroxidase activity, but drought induction. Moreover, population variations had a significant effect on chlorophyll a, chlorophyll b and peroxidase activity. Among all the measured samples, the Khalkhal population had the highest content of photosynthetic pigments, soluble sugars and peroxidase activity. However, the Kahak population had the lowest value of the mentioned traits instead of the latter trait. Meanwhile, the severe drought stress produced the highest peroxidase activity, carotenoid, proline, protein, soluble sugar contents. By contrast, the lowest values of the mentioned traits were achieved in well-water treatment. The highest chlorophyll a, chlorophyll b and total chlorophyll contents were observed in 70% FC, while the lowest were recorded in 20% FC. The Khalkhal population × severe drought stress produced the highest carotenoid, soluble sugar content and peroxidase activity, and also, Khalkhal population × moderate drought stress recorded the highest contents of phosynthetic pigments. Therefore, the Khalkhal population could be introduced as suitable Achillea vermicularis population in Iran.