| Polygonatum odoratum（mill.）Druce)as one of the genuine medicinal materials of the bulk brand"Xiangjiuwei"in Hunan Province,the output accounts for more than 70%of the total output of P.odoratum in China.The Pharmacopoeia of the people’s Republic of China（2020）stipulates that P.odoratum polysaccharide,calculated as glucose(C6H12O6),shall not be less than 6.00%.In the production of P.odoratum,the polysaccharide content of some products was lower than the standard of Pharmacopoeia,the current classification standard was single.In this study,131 batches of fresh medicinal materials and processed products of P.odoratum were randomly selected from the planting bases,processing plants and drug stores in the main production areas of P.odoratum,such as Shaodong County,Guiyang County,Anhua County,Xupu County and Cili County in Hunan Province,the polysaccharide content was determined,and the quality of P.odoratum was analyzed by X-R control chart and K-means clustering method.On this basis,the changes of P.odoratum polysaccharide content in different growth years,rhizome age sections,varieties,harvest time,surface covering,processing and storage were studied,and the correlation between polysaccharide content and plant photosynthetic characteristics,agronomic characters and other growth characteristics in two surface covering treatments of grass covering and soil covering were analyzed.The main results are as follows:（1）The X-R control chart shows that the polysaccharide content of 131 batches of P.odoratum was 3.39%～10.53%,of which the control range was 5.41%～7.96%including all batches of fresh P.odoratum medicinal materials,86.67%P.odoratum slices,21.43%P.odoratum strips and 40.00%P.odoratum leftover materials,according to the standard of Pharmacopoeia,there were 5.15%fresh P.odoratum medicinal materials and 40.00%P.odoratum leftover materials in the range of 5.41%～6.00%,and there were 6.67%P.odoratum slices and 40.00%P.odoratum leftover materials in the range of 3.39%～5.41%,6.67%P.odoratum slices and 78.57%P.odoratum strips in the range of 7.96%～10.53%,the polysaccharide content of 5.15%fresh P.odoratum medicinal materials and 6.67%P.odoratum slices in normal cultivation and processing was less than 6.00%.The polysaccharide content of P.odoratum was divided into five categories by K-means clustering method:Class A was 3.39%～5.00%,the samples contained were the same as3.39%～5.41%of the samples in the X-R control chart;Class B was 5.00%～6.00%,the samples contained were the same as 5.41%～6.00%of the sample in the X-R control chart;Class C was 6.00%～7.00%,included 86.60%fresh P.odoratum medicinal materials,73.33%P.odoratum slices,7.14%P.odoratum strips and 20.00%P.odoratum leftover materials;Class D was 7.00%～9.00%,included 8.25%fresh P.odoratum medicinal materials,16.67%P.odoratum slices and 42.86%P.odoratum strips;Class E was 9.00%～10.53%,included 50.00%P.odoratum strips;In the fresh P.odoratum medicinal materials,there are some Ciwei P.odoratum,2-year-old,5-year-old and P.odoratum with green skin the content of polysaccharide were less than 6.00%.（2）Based on X-R control chart,K-means clustering method and current standards,P.odoratum was divided into three types:fresh P.odoratum medicinal materials,P.odoratum slices and P.odoratum strips,and divided into grades:P.odoratum strips with polysaccharide content greater than 9.00%are first-class medicinal products,7.00%～9.00%are second-class medicinal products,and 6.00%～7.00%are third-class medicinal products;fresh P.odoratum medicinal materials and P.odoratum slices with polysaccharide content greater than 7.00%are first-class medicinal products,and 6.00%～7.00%are second-class medicinal products;5.00%～6.00%of all types of P.odoratum were edible grade products,and less than 5.00%were comprehensive development and profit-making products.（3）The change law of P.odoratum polysaccharide content was studied from different growth years and rhizome age sections.The change law of P.odoratum polysaccharide content in different growth years showed that the polysaccharide content of 1-year-old P.odoratum increased in the whole growth period,and the polysaccharide content of2-year-old,3-year-old and 4-year-old P.odoratum decreased first and then increased;The polysaccharide content of 3-year-old P.odoratum was the largest.The polysaccharide content of 3-year-old P.odoratum in October was significantly higher than that of 4-year-old,2-year-old and 1-year-old P.odoratum（P<0.05）.The change law of polysaccharide content in different rhizome age sections of P.odoratum showed that in the four growth years,the polysaccharide content in the first and second age sections of P.odoratum increased in the whole growth period,the polysaccharide content in the third age section of P.odoratum decreased first and then increased,and the polysaccharide content in the fourth and mixed age sections of P.odoratum decreased;The polysaccharide content of rhizome in the second age section of P.odoratum was the largest and that of seed stem was the smallest.The polysaccharide content of the second age section of P.odoratum was significantly higher than that of mixed age section,third age section,first age section,fourth age section and seed stem age section of P.odoratum.The change law of P.odoratum polysaccharide content was studied from different varieties and harvest time.Among them,the change law of P.odoratum polysaccharide content of different varieties showed that the polysaccharide content of P.odoratum increased first and then decreased from August to December.There were significant differences in polysaccharide content of P.odoratum among different varieties.The polysaccharide content of Honggan Zhushiwei P.odoratum and Lvgan Zhushiwei P.odoratum were significantly higher than that of Ciwei P.odoratum and Zhushiwei P.odoratum（P<0.05）.The polysaccharide content of Honggan Zhushiwei P.odoratum had the maximum in late September.The polysaccharide content of Ciwei P.odoratum,Zhushiwei P.odoratum and Lvgan Zhushiwei P.odoratum had the maximum in mid October.The change law of polysaccharide content in P.odoratum at different harvest times showed that the best harvest time of 3-year-old P.odoratum was from September to October.From August to December,the polysaccharide content of P.odoratum from Shaodong County,Guiyang County,Anhua County,Cili County,Xupu County and Xinhua County increased first and then decreased.In late September,the polysaccharide content of P.odoratum from Shaodong County and Guiyang County reached the maximum,and in mid October,the polysaccharide content of Polygonatum odoratum from Anhua County,Xupu County,Cili County and Xinhua County reached the maximum,the polysaccharide content of P.odoratum reached the peak from September to October..（4）1-year-old P.odoratum was treated under grass covering,2-year-old and 3-year-old P.odoratum were treated under soil covering,and the effect of surface covering treatment on P.odoratum polysaccharide content showed that grass covering had no significant effect on the polysaccharide content of 1-year-old P.odoratum rhizome,and soil covering could significantly increase the polysaccharide content of 2-year-old and 3-year-old P.odoratum rhizome.There was no significant difference in rhizome polysaccharide content between1-year-old P.odoratum was treated under grass covering and control P.odoratum in the whole growth period;The content of rhizome polysaccharide in the mixed age section of2-year-old P.odoratum and 3-year-old P.odoratum were treated under soil covering was significantly higher than that of the control P.odoratum（P<0.05）,and the content of rhizome polysaccharide in the first and second age sections of 2-year-old P.odoratum and3-year-old P.odoratum were treated under soil covering was also significantly higher than that of the control P.odoratum.The study on polysaccharide content and growth correlation showed that the polysaccharide content of rhizomes of 1-year-old P.odoratum had a very significant positive correlation with that of the first age section of P.odoratum;The content of polysaccharide in rhizome of 2-year-old P.odoratum was significantly positively correlated with the content of polysaccharide in the first age section of P.odoratum,the content of polysaccharide in the second age section of P.odoratum,leaf area index,net photosynthetic rate and rhizome diameter;The content of polysaccharide in rhizome of3-year-old P.odoratum was significantly positively correlated with the content of polysaccharide in the first,second and third age sections of P.odoratum,leaf area index,stomatal conductance and rhizome diameter.Soil covering promoted the accumulation of polysaccharide content in rhizomes of 2-year-old and 3-year-old P.odoratum by increasing the polysaccharide content in rhizomes of the first and second age sections of P.odoratum,as well as the net photosynthetic rate,leaf area index and rhizome diameter of P.odoratum.（5）The effects of different processing and storage treatments on the polysaccharide content of P.odoratum products were studied.The study on the polysaccharide content of different processing parts of P.odoratum showed that the polysaccharide content of P.odoratum rhizome after removing the skin and fibrous roots was significantly increased.The polysaccharide content of P.odoratum rhizome skin was 2.52%,accounting for 35.75%of the P.odoratum crude rhizome;The polysaccharide content of P.odoratum rhizome fibrous root was 2.01%,accounting for 28.96%of the P.odoratum crude rhizome.The polysaccharide content of P.odoratum rhizome flesh was significantly higher than that of the P.odoratum crude rhizome（P<0.05）.Effects of different processing methods on polysaccharide content of P.odoratum:Rubbing can significantly improve the polysaccharide content of P.odoratum strip,and P.odoratum slice were more suitable for drying processing.The polysaccharide content of rubbed P.odoratum strip was 8.03%,which was significantly higher than that of steamed P.odoratum strip,mechanically rolled P.odoratum strip and air dried P.odoratum strip;The polysaccharide content of dried P.odoratum slices was significantly higher than that of air dried P.odoratum slices.The effects of different storage methods on the polysaccharide content of P.odoratum showed that the effect of low-temperature sealed storage of P.odoratum products was better.After one year of storage,the polysaccharide content of P.odoratum stored in open storage at room temperature was significantly lower than that of P.odoratum sealed storage at room temperature and P.odoratum sealed storage at low temperature. |
