Effects Of Nitrogen Sedimentation And Salinity Stress On Eco-physiological Characteristics And Quality Of Saposhnikovia Divaricata

Saposhnikovia divaricata(Miq.)Schischk.is a perennial herbaceous plant in Umbelliferae,which is one of the common Chinese herbs in China.Their unbolting roots can be used as medicines,which has activities against various human diseases and conditions,including antipyretic,analgesia,antioxidatio,anti-inflammatory,inhibition of platelet aggregation and anticlotting.Nitrogen and saline-alkali stress are important environmental limiting factors affecting plant growth and productivity in the western of Jilin Province.Therefore,in this study,the effects of different salt-alkali stress treatments on growth characteristics,physiological and ecological characteristics and quality of S.divaricata were systematically studied through artificial simulated nitrogen deposition,this research can provide theoretical basis for its planting and ecological control of medicinal materials quality.The main conclusions are as follows:1.Effects of salt-alkali stress on the growth characteristics of S.divaricata in different nitrogen treatmentsMild salt-alkali stress could promote the growth and biomass accumulation of S.divaricata.The root diameter,fresh and dry biomass of S.divaricata were higher than those of the control in the salt stress of 200 m M when the nitrogen was 0g/m~2and 10 g/m~2.The root diameter,fresh and dry biomass of S.divaricata in 200 m M salt stress was significantly higher than those of the control and 400 m M alkali stress,the growth and biomass of S.divaricata were inhibited in severe alkali stress.2.Effects of salt-alkali stress on physiology and ecology of S.divaricata in different nitrogen treatmentsthe content of proline increased with the increasing of salt stress,and the content of proline in 400 m M and 600 m M salt stress were significantly higher than those of control when nitrogen was 0 and 10 g/m~2.the proline content of 400 m M alkali stress was significantly higher than those of the control group and 200 m M alkali treatment in no nitrogen treatment.The soluble sugar content of 200 m M alkali stress was significantly higher than other treatments in the nitrogen was added 0 g/m~2and 10 g/m~2.The results of this study showed that the addition of nitrogen can increase the ability of S.divaricata resistance to salt-alkali stress.SOD activity in 600 m M salt stress was significantly higher than other treatments and the POD activity in CK was significantly higher than other treatments when nitrogen was added 0g/m~2.There were no significant differences in SOD and POD activity among salt-alkali stress treatments with the increasing of nitrogen.The trend of enzyme activity of CAT was consistent with SOD.Content of chloroplast A,chloroplast B,chloroplast A+B and carotenoid in leaves of S.divaricata in mild salt stress were higher than those of control in different nitrogen treatment.The contents chloroplast A,chloroplast B,chloroplast A+B and carotenoid decreased with the increase of salt stress.While the there is an opposite trend for the chloroplast content in the alkali stress.3.Effects of salt-alkali stress on the quality of S.divaricata in different nitrogen treatmentsMild salt-alkali stress promoted the prim-O-glucosylcimifugin content from S.divaricata.The 5-O-methylvisamminol content increased in the mild salt stress,but decreased in the alkali stress.The 4 kinds of chromones content from S.divaricata increased in the mild salt stress,while there is no significant effect on 4 kinds of total chromones from S.divaricata in alkali stress.