مشخصات پژوهش

Plant growth and development are highly dependent on light intensity, as light is a limiting factor for plant growth, yield, physiological and phytochemical processes. Ziziphora clinopodioides is a well-known aromatic and culinary species of the genus Ziziphora. It has been used in Iranian folk medicine to treat digestive problems and fever, and is distributed worldwide, especially in Iran [1-3]. Field experiments were conducted to measure chlorophyll a and chlorophyll b content, carotenoid content and yield of Z. clinopodioides under three light intensities (full sunlight, 75% and 50% of full sunlight). The results showed that plants exposed to low shade (75% light intensity) had increased chlorophyll a, chlorophyll b and decreased carotenoid content and total dry yield. The results showed that as light intensity increased, carotenoid content increased and the amount of dry matter also increased, but chlorophyll and fresh matter content decreased. This disruption in photosynthesis led to a significant decrease in both fresh and dry matter yield of the plants. In general, the results showed that Z. clinopodioides showed a negative response to the intensity of low and high light and its yield was reduced because of the photosynthetic pigment.