Özgür Tatar

Plant-soil Water Status-induced Changes in Physiological and Biochemical Properties of Yarrow

Abstract As medicinal plants are generally collected from the wild flora, it is of fundamental importance to identify the optimum growth conditions for increasing the yield and quality potential of ex-situ cultivated plants. Effects of different soil water content [20, 40, 60 and 80% of water holding capacity (WHC)] on growth, physiology and biochemical profile of Achillea millefolium group-related cv. Proa were investigated in the present study. Alterations in drug herbage, chlorophyll content, quantum efficiency of photosystem II, essential oil rate and composition, proline content and lipid peroxidation, antioxidant activity and flavonoid content of the plants under different plant and soil water status were determined. Decrease in soil water status under 40% of WHC resulted in degradation of chlorophyll pigments, reduction in photochemical efficiency and lower dry matter production. The essential oil (EO) rate of cv. Proa was higher under limited and excessive water content of soil whereas the main component of EO, chamazulene, was negatively correlated with WHC of soil. Our results suggest a general trend of inverse correlation of antioxidant capacity and flavonoid content with essential oil rate in contrast to the positive correlation of these parameters with chamazulene content. The data obtained may serve as a basis of programming the optimum soil moisture conditions for successful cultivation of cv.Proa.

Physiological and Biochemical Responses of Achillea Millefolium Group-Related Cultivar Proa to Different Nitrogen Regimes

ABSTRACT In the present study the effect of different nitrogen amounts (0 g [N0], 0.45 g [N1], 0.9 g [N2] and 1.35 g N [N3] per pot, corresponding to 0 kg·ha−1, 50 kg·ha−1, 100 kg·ha−1 and 150 kg·ha−1 N application in field conditions) and application times (at sowing, vegetative stage and pre-bloom stage) on the yield, relative water content, total nitrogen content and nitrogen use efficiency in plants of the Achillea millefolium group-related cv. Proa was investigated. Antioxidant activity, flavonoid content, rate and composition of the essential oils were also determined. Application of N2 increased the dry herbage and flos production, total nitrogen amount and nitrogen use efficiency, without affecting the essential oil rate while reducing the antioxidant activity. Higher amounts (N3] of nitrogen maintained the dry herbage and flos yield at levels similar to N2 but decreased the antioxidant activity and rate of the essential oil. The major component of the essential oil, chamazulene, was negatively (N1, N2) or not influenced (N3] by the nitrogen application, while variable changes were registered in the content of the other components. The data point to the nitrogen regime being a subtle tool for regulating the performance of cv. Proa plants.