Effects Of Shading Treatment On The Growth And Photosynthesis Characteristics In Several Medicinal Plants

Mesona chinensis Benth., also known as immortality, is a kind of Labiatae family, Mesona genus and annual herbage plant, the whole plants are used as Chinese herbal medicine. Schizocapsa plantaginea Hance,also called Water Panax or radish, is Taccaceae family and Schizocapsa enera perennial herb. Its dry tubers are used as Chinese herbal medicine. Daphniphyllum calycinum Benth, which is also called goat feces or tiger ears, is a plant of Daphniphyllaceae family and Daphniphyllaceae genera. Its stems with leafy shoots is used as Chinese herbal medicine. Commonly used as herbal medicinal plants in Guangxi region, these three have a high medicinal value and broad base of the masses application. In this study, the three medicinal plants as the test materials, We aim at to research that different shading treatment have different impacts on agronomic traits, chlorophyll content and photosynthetic characteristics in the three medicinal plants. Test results were as follows:(1) Shading treatment could increased the plant hight, node length and petiole length of Mesona, also the plant hight and petiole length of schizocapsa plantaginea and Daphniphyllum calycinum and could reduce the steam crude and steam-folded rate of Mesona, Schizocapsa plantaginea and Daphniphyllum calycinum.(2)When shading rate was50%, total chlorophyll content of Paitan immortality was the highest. While shading rate was25%, total chlorophyll content of three armor immortality was the highest. The total chlorophyll content of Vietnam immortality and the paddy field seven and Daphniphyllum calycinum was the highest in the environment of shading rate of75%. The test results show that effects of several shading treatment on chlorophyll content of medicinal plants of each were not identical. Through the test to screen out the suitable shading rate,which can increase the content of chlorophyll in plants and promote the photosynthesis.(3)In terms of the amount of change from the net photosynthetic rate, intercellular concentration changes of CO2during a day, and the amount of changes from stomatal conductance and transpiration rate within a day, Paitan Mesona was more suitable for growing in the no shade environment or in the environment of shading rate of25%. photosynthetic performance of three armor immortality is better in the shading rate of25to50%.(4)After the four treatment the trend of the Schizocapsa plantaginea and Daphniphyllum calycinum and the light intensity of reaction curve has some similarities. Generally, net photosynthetic rate of this two kinds of medicinal plants in the environment of shading rate of75%was higher than that of shading rate was50%and the shading rate of25%, and was significantly higher than that in the environment of shading rate of0%for the control group. It can be proved that the paddy field seven and Daphniphyllum is more suitable for growing in highly shady rate environment.