Abstract

The effect of water stress, excess water and water deficit, on the leaf relative water, amounts of proline, water soluble sugars and total chlorophyll and chlorophyll a, b were examined, to characterize the involvement of these components in the adaptive processes. An experiment was carried out with four irrigation levels (W1, W2, W3 and W4 consisting 100, 85, 70 and 55% of field capacity, respectively) arranged in randomized complete block design with five replications. Potted seedlings of Matricaria chamomilla were used as a test medicinal plant. Leaf relative water content, percentage of proline and total soluble sugar were not affected by irrigation regimes. But, irrigation had significant effect on amount of total chlorophyll and chlorophyll a, b. The maximum amount of chlorophyll a (19 mg/g), chlorophyll b (16 mg/g) and total chlorophyll (35 mg/g) obtained from W2 and W3. The minimum amount of chlorophyll a (15 mg/g), chlorophyll b (11 mg/g) and total chlorophyll (26 mg/g) obtained from W1, W4, W4, respectively. The values of total chlorophyll and chlorophyll a, b were the same in irrigation, at 100 and 55% of field capacity.

Key words: Drought stress, irrigation, Matricaria chamomilla, osmolytes, proline, soluble sugar.