Study on leaf transpiration and stomatal structure of medicinal plant Tetrastigma hemsleyanum / 中草药

ABSTRACT

Objective: Taking annual Tetrastigma hemsleyanum (Tetrastigma Radix) from three habitats, Taizhou, Minhou, and Shunchang, as materials to study the effects of different light intensity stress on the stomatal shape and leaf transpiration. Methods: The stomata, leaf transpiration rate, net photosynthetic rate, and stomal structure of T. hemsleyanum were observed using a scanning [0-2000 μmol/(m2·s)] to explore the optimal light intensity. Results: The stomata with surround and parallel distribution types were only distributed in the lower epidermis in the leaves of T. hemsleyanum; The transpiration rate, stomatal conductance, and net photosynthetic rate of T. hemsleyanum from the two habitat regions (Minhou and Taizhou) by rising after falling with the 30℃ stress, which suggested the stress could make the light intensity heavier. At the same time, the transpiration rate, stomatal conductance, and net photosynthetic rate of T. hemsleyanum from the habitat region Shunchang were rising. The stomatal type of leaves was 600 μmol/(m2·s) in Minhou, and 1900 μmol/(m2·s) in Shunchang, when the water utilization ratio of T. hemsleyanum leaves from the three habitats was higher. Conclusion: Different habitats and light intensity are the important factors of leaves transpiration in natural world, which is more beneficial to the growth of the root crops and suitable for the accumulation of flavonoids in plants.