Effect Of Previous Crop On Continuous Cropping Obstacle Of Panax Notoginseng

Panax notoginseng(Burk)F.H.Chen,as one of the traditional Chinese medicinal herbs,is credited with the effect of giving birth to health and eliminating ripening.With the development of new uses,the market demand for P.notoginseng is also increasing,and the planting range of P.notoginseng is narrow,so continuous cropping obstacle has been considered as the main problem restricting the development of P.notoginseng industry.At present,a series of solutions to continuous cropping obstacles have been proposed,such as physical landfill,chemical reagent disinfection,strong reducing agent treatment,etc.In consideration of the green and sustainable concept,this study selected crop rotation to treat the seven sites.The effects of different cropping rotations on P.notoginseng plants,soil and microorganisms were studied.In the one-year follow-up experiment,the dynamic changes of P.notoginseng crop growth and soil microecological activities were analyzed,and the key factors of crop rotation were found to provide theoretical basis for the improvement of P.notoginseng planting system and the alleviation of continuous cropping obstacles.The main results are as follows:1.With eight different crop rotation after continuous cropping of P.notoginseng samples as the research object,measuring the plant height,stem circumference,leaf length,leaf width,petiole,and production related data including root length,root weight and so on,to explore the influence of different crop rotation biomass accumulation of P.notoginseng,eventually found the corn and coix seed crop rotation has a sharp rise in the yield and biomass of P.notoginseng.2.In continuous cropping land,for comparison,P.notoginseng light after the eight different crop rotations and parameters and defensive enzyme content and other physiological indicators for testing,for five years after continuous cropping rotation notoginseng resistance index were evaluated,the results showed that crop rotation photosynthetic parameters of P.notoginseng were significantly increased,and at the same time reduces the content of antioxidant enzymes,including on grain crops,corn and coix seed reduce most;3.In the detection of soil nutrients,physical and chemical properties and soil enzymes of P.notoginseng,it was found that soil physical and chemical properties,soil enzyme activities and soil nutrients were improved and promoted in different degrees after crop rotation.Soil microbial diversity and richness of P.notoginseng were analyzed by 16 Sr RNA and ITS amplification sequencing method.Crop rotation significantly increased the microbial expression abundance of P.notoginseng,especially maize rotation.At the same time,Trichoderma,an antagonist against continuous cropping disorder,was found.Environmental factors were used to analyze bacterial and fungal communities,and soil physicochemical properties and microorganisms were preliminarily explored.4.Different preceding alleviate the toxic effect of P.notoginseng ability,using HPLC and q PCR technology of P.notoginseng saponins class since the amount of poisonous substance content and key synthetic gene expression change has carried on the test,the results showed that different crop rotations before significantly reduces the P.notoginseng saponins class since the poisonous substance content,key gene expression and saponins from toxic substances content changes.At the same time,correlation analysis showed that the autotoxic substances significantly increased the activity of antioxidant enzymes,and inhibited the photosynthetic rate,stomatal conductance,transpiration rate,etc.