ABSTRACT
Objective To study the physiological characteristics of Codonopsis Radix under drought stress; To reveal the physiological mechanism of Codonopsis Radix in response to drought stress. Methods Method of pot experiment was used to set up 4 water treatments: normal water supply, mild stress, moderate stress and severe stress. Through the determination of leaf relative water content, cell membrane permeability, osmotic adjustment contents and protective enzyme activity, the effects of drought stress on physiological characteristics of Codonopsis Radix were studied. Results With the drought stress increased, the chlorophyll a, total chlorophyll content and leaf relative water content of Codonopsis Radix decreased, but chlorophyll b had no obvious change; The conductivity increased first and then decreased; MDA contents increased first and then decreased and then increased; There was no significant change in the rate of superoxide anion production; POD and CAT activity increased; SOD had no significant change; The proline content increased first and then decreased; soluble sugar decreased; soluble protein had no significant change. Conclusion Under the condition of drought stress, by increasing the content of proline to regulate cell osmotic potential, Codonopsis Radixcan increase the antioxidant enzyme activity to reduce membrane lipid peroxidation damage to cells.
ABSTRACT
The study is aimed to research the relationship between the seedling grade of Codonopsis pilosula and yield and quality of medicinal materials, so as to provide basis for establishing seedling standard. Thirty seedlings of C. pilosula were collected from the main production areas in Gansu province, such as Weiyuan, Minxian, Zhangxian, Dangchang and Longxi, root length and diameter and weight of all the samples were measured. According to the clustering results, seedlings were divided into 3 levels, and field experiments were conducted with three levels seedling, yield and quality were tested in laboratory. Results have showed that emergence of grades 1 was faster than that of grades 2 and 3. Yield of grades 1 was significantly higher than that of grades 2 and 3 (P<0.05). Propargyl glycoside content of grades 1 was the highest, and significantly higher than that of grades 3. Polysaccharide content of grades 3 was the highest and significantly higher than that of grades 1 and 2 (P<0.05). So considering yield, quality and investment cost of C. pilosula, planting seedlings of C. pilosula should select that root length>15.6 cm, root diameter>2.7 mm, root weight>0.56 g.