The Study On Prospects Of Utilization And Development And Biological Characteristics Of Datura Stramonium L. In Qinghai Province

We studied the growth and botanical characteristics of Datura stramonium L.bv observing them in fixed locations in the field.The characteristics of Datura stramonium L.community quantity was analyzed by minimum sampling approach.We studied the seed germination rate,seedling-rearing and transplanting of wild Datura stramonium L.in artificial cultivation in Xining area.The characteristics of photosynthesis before and after artificial cultivation, including photosynthetic pigment,net photosynthetic rate,stomatal conductance, transpiration and intercellular CO₂ concentration,were studied by using portable photosynthesis analyzer.The resistance characteristics,including superoxide dismutase(SOD) activity,peroxidase(POD) activity and catalase(CAT) activity, malondialdehyde(MDA) content were also studied.Our results demonstrated that Datura stramonium L.is an annual herbaceous plant in Qinghai Province.It mainly grows in east agricultural area with altitude of 1700m - 3200m and in the area of Huangnan and Jianzha.Wild Datura stramonium L.is the dominant species in it's main distribution area, while the specie associated is mainly Poa.In Xining area,the plant growth phenology of wild Datura stramonium L.can be divided into six stages, including stages of emerging,seedling,branching,flowering,fruiting,and wilting.Datura stramonium L.has a longer growing period in cultivation than in the wild,with an earlier nutritional growth and reproductive growth,and a later fusarium period.Mechanic wearing of the seeds coat interrupts the dormancy of the seeds and significantly increases germination rate.The germination rate can also be improved by GA treatment.The optimal treatment combinations for seeds stored at -10℃is mechanic wearing followed by 200 ppm GA treatment. The germination rate for these seeds is 88%at room temperature.For seeds stored at room temperature,the optimal combination is mechanic wearing followed by 1%KNO₃ treatment,and the germination rate of these seeds at room temperature is 92%.The germination rate of wild Datura stramonium L is 35.3% and the survival rate of transplanted wild Datura stramonium L.is 80%.Both the fresh and dry whole-plant weight increased significantly in cultivation,with an increase of fresh weight from 1.166kg to 2.2367kg and a dry weight increase from 0.2137kg to 0.4086kg.The concentration of Chla and Chlb is higher in cultivated than in wild Datura stramonium L.,so does the Chla/Chlb ratio.The concentration of Car is higher in the wild Datura stramonium L..The daily progress of photosynthesis rate(Pn) exhibits double -peak curve with the phenomenon,of "noon break".The maximum net photosynthesis rate of wild Datura stramonium L.is higher than wild species.Transpiration rate rises with temperature from morning.When the combined effect of temperature and humidity reaches the optimal point,photosynthetic rate reaches its maximum value.The change of CO₂ concentration tends to be consistent,when the temperature reaches some point,intercellular CO₂ concentration maintains at a stable level.The power of lightening and speed of evaporation affects photosynthesis rate.The activities of SOD,POD,CAT in cultivated and the concentration of MDA are significantly higher in wild than in cultivated Datura stramonium L.Based on our data,the utilizaiton and development of Datura stramonium L should be based on protection.We should create technologies to efficiently harvest,store,and process Datura stramonium L,and develop a series of Datura stramonium L.based products special for Qing-Tibetan area,turning the natural resource advantages into economy advantages.It should be the reasonable way for the utilization and development of the wild Datura stramonium L.in our province.This is the first systematic study on natural resources for wild Datura stramonium L.in Qinghai Province.This study built up strong bases for proper utilization and development of wild Datura stramonium L.,and accumulated valuable information in photosynthesis and resistance of plants in Qinghai province.