Effects Of Different Soil Moistures On Water Consumption Characterstics And Contents Of Active Components Of Aconitum Carmichaeli Debx.

Radix aconitilateralis preparata is the lateral root of Aconitum carmichaeli Debx., a kind of medicinal plant. In this paper, the effects of different soil water contents on the water-consumption characteristics, growth dynamic, physiological responses, content of active components were systematic studied by pot cultivation experiment, irrigation and drainage system were studied too. The results are expected to provide scientific basis of standardized water administration in practical planting. The main results were as follow:1. During the whole growth stage of 100d, under high soil water treatment, suitable soil water treatment and moderate water stress treatment, the water consumption was 30.416kgH₂O per plant, 22.483kgH₂O per plant and 15.514 kgH₂O respectively. Water–consumption between the end of May and the middle of June was more than 38% of whole, which was significant higher than that middle of June. Series changes of water consumption and transpiration rates in daytimes were measured, the curves showed two high points in sunshine days, whereas a relatively low water consumption and transpiration rate appeared in noontime. Contrast to suitable soil water treatment, the average water consumption and transpiration rates of moderate water stress treatment decreased 63.75% and 42.12% respectively, decreased 50.83% and 20.97%, contrast to high soil water treatment.2. The average height of stems increased 22.54% and 62.31% respectively under high soil water treatment and suitable soil water treatment; the average length between two leaves were higher 15.12% and 46.54% respectively than that of moderate water stress treatment and the average length of leaves increased 8.08% and 22.22%. Under suitable soil water treatment the diameter and numbers of root increased remarkably. During the drought period ,water content descended; chl. content increased in early stage while decreased in later stage ; content of MDA ,SOD activity ,POD activity ,CAT activity were stable under suitable water stress; in root enlarging period content of polysaccharose was higher and higher under moderate water stress. Under moderate water stress, changes of Pn,Tr and Gs were similar ,and showed two high points. Under moderate water stress treatment, the weight of root increased slowly. Contrast to high soil water treatment, the root yield of moderate water stress treatment descended 27.65%, the root yield of suitable soil water treatment descended 21.05% too. In root enlarging stage soluble sugar was increasing. Under moderate water stress treatment, the alkaloids increased quickly, moderate drought circumstances accelerated accumulation of alkaloids. The period of the end of May and the middle of June was crucial for accumulation of alkaloids.3. In different growth stages, high soil water, moderate water stress and suitable water stress were carried out; the results indicated that water-consumption, yield and active components content were significant in different treatment. The water-consumption of which suitable water stress applied in whole stages was lower than that of whichever growth stages applied high soil water, higher than that of whichever growth stages applied moderate water stress. High soil water favored the growth of stems and leaves, but disadvantaged the growth of root. Neither stems and leaves nor roots grew well under moderate water stress. In early period of root enlarging, moderate water stress accelerated accumulation of alkaloids. Content of alkaloids was sensitive to soil water, high soil water decreased it, while moderate water stress increased content of alkaloids, but it loss larger under high soil water provided in root enlarging stage.By selecting two indexes: root yield and content of alkaloids applying the comprehensive appraisal index, we assessed the quality of lateral root of Aconitum carmichaeli in different treatment: whole growth stages provided suitable soil water-high soil water-suitable soil water was the best, whole growth stages provided suitable soil water was the second .4. Based on water requirement law of Aconitum carmichaeli debx., precipitation distribution and soil condition of planting areas, preliminary irrigation and drainage system was advanced: (1) in fast growing period, when the average soil water between 0～40cm is less than15.96% irrigating; (2) in root enlarging early period stage, when the average soil water between 0～20cm is less than 19.38%,irrigating; (3) in root enlarging late period stage, when the average soil water between 0～20cm is less than 15.96%,irrigating; (4) whole growth stage, when the average soil water between 0～40cm is more than 19.38%, must carried out drainage measures.