Effect Of Crop Rotation On The Accumulation Of Main Active Components And Processing Quality Of Rehmannia Glutinosa

Rehmannia glutinosa,a perennial herb of the Scrophulariaceae family,is of high edible and medicinal value.The yield and quality are severely restricted by continuous cropping obstacles in the cultivation of R.glutinosa.At present,the formation mechanism of continuous cropping obstacles has been preliminary analyzed,but the reduction technology of cropping obstacles is awaiting to be further developed and the reduction effect of crop rotation on continuous cropping obstacles of R.glutinosa has not been reported.In this research,R.glutinosa cultivar "Wen 85-5" was used as the material.The first stubble or continuous cropping was used as the control,and four kinds of rotation(R.glutinosa /Achyranthes bidentata / R.glutinosa,R.glutinosa / Dendranthema morifolium / R.glutinosa,R.glutinosa / Zea mays / R.glutinosa,R.glutinosa / Arachis hypogaea / R.glutinosa)were used as treatment.The agronomic characteristics,physiological activity,and yield of R.glutinosa under different rotating methods were determined to analyze the growth and development of rotating R.glutinosa.The contents of the main active components of R.glutinosa under different rotating methods were determined to analyze the accumulation pattern of the main active compounds of rotating R.glutinosa.The quality of rotating R.glutinosa under different processing methods was detected to analyze the influence of processing methods on the quality of rotating R.glutinosa.The main results are as follows:(1)The agronomic traits including the emergence rate,leaf numbers,leaf maximum area,and the biomass,the physiological indicators including POD enzyme activity,SOD enzyme activity,and soluble protein content and the yield indicators including the number of roots per plant and so on of R.glutinosa were determined.The results showed that: the growth and development of rotating R.glutinosa,compared with continuous cropping R.glutinosa,is significantly improved,which is specifically manifested as enhanced growth,increased biomass,increased SOD and SOD enzyme activities,and increased soluble protein content.The yield of rotating R.glutinosa was significantly higher than that of continuous cropping R.glutinosa.Compared with the root quality of three-year continuous cropping R.glutinosa,the root quality of R.glutinosa under the rotation of A.bidentata,D.morifolium,Z.mays,and A.hypogaea was increased by 148.75%,126.95%,79.18%,and 38.15%,respectively.(2)Phenol-sulfuric acid,Folin-phenol,and HPLC methods were used to determine the content of the main active compounds in rotating,continuous cropping,and first stubble R.glutinosa.The results showed that: the content of polysaccharides,catalpol,acteoside,and rehmannioside D was higher than that of continuous cropping R.glutinosa.The content of four active compounds in R.glutinosa under the rotation of A.bidentata was the highest.Compared with the three-year continuous cropping R.glutinosa,its content of polysaccharides,catalpol,acteoside,and rehmannioside D was increased by 29.22%,13.83%,39.13%,and 66.67%,respectively.(3)The appearance and flavor,water content,extract content and the content of main active compounds of the processed R.glutinosa were detected.The results showed that:there was no obvious difference in appearance and flavor between rotating and first stubble R.glutinosa,and they all complied with the national standards.Under the different processing methods,the water content of Rehmanniae Radix under the rotation of D.morifolium after freeze-drying processing is the lowest,only 10.72%.The extract content of Rehmanniae Radix Praeparata under the rotation of A.bidentata after the wine-stewing processing is the highest,reaching 90.14%.In all samples,the polysaccharides content of Rehmanniae Radix Praeparata is significantly higher than that of Rehmanniae Radix,and the contents of catalpol and acteoside in Rehmanniae Radix were significantly higher than those in Rehmanniae Radix Praeparata.There was no significant change in the rehmannioside D content between Rehmanniae Radix Praeparata and Rehmanniae Radix.In summary,the effects of continuous cropping obstacles on the growth and development,accumulation of active ingredients and processing quality in R.glutinosa can be reduced by A.bidentata rotation and D.morifolium rotation,which are effective measures to reduce the obstacles to continuous cropping of R.glutinosa.Meanwhile,the processing quality of rotating R.glutinosa complies with national regulations and can be used in the processing and development of dietary supplement.