Study On The Influence Of Key Planting Techniques On The Quality Of Platycodonis Radix

Platycodon radix is one of the commonly used bulk medicinal materials in China,and it also belongs to the"homology of medicine and food"variety,and the market demand is large.In recent years,with the decrease of wild platycodon grandiflorum（P.grandiflorum）resources,cultivated P.grandiflorum has become the main source of Platycodon radix,but the problem of uneven quality of Platycodon radix from different habitats has also followed.According to the investigation,the quality of artificially cultivated medicinal materials is closely related to its planting techniques.Tongliao,Inner Mongolia is one of the Platycodon radix producing areas in China.However,due to the differences in climatic conditions,growth periods,special sandstorms and farming habits,the existing planting techniques of Platycodon radix in other producing areas are not suitable for Tongliao,and there is a lack of exclusive technical guidance for Platycodon radix planting in this area.In order to ensure the quality of Platycodon radix in Tongliao,Inner Mongolia,and select the planting techniques suitable for Platycodon radix in Tongliao,this study used P.grandiflorum seeds from different habitats and different treatment factors as materials,determined the indexes of the collected P.grandiflorum seeds from main habitats,and established the quality grading standards of P.grandiflorum seeds.Taking Tongliao,Inner Mongolia as the experimental site,the related indexes of Platycodon radix under different planting techniques were determined,and a multi-index quality evaluation system of Platycodon radix was established,and the effects of key planting techniques of Platycodon radix on its quality were studied.The results are as follows:1.Study on seed quality standard of P.grandiflorum.There are obvious differences in the indexes of 19 P.grandiflorum seeds from different habitats,and the differences of the indexes are different.The main indexes of quality grading of seeds were screened out,such as 1000-seed quality,cleanliness and germination rate,and the quality grading standards of seeds were initially established:I-class seeds with 1000-grain weight≥1.0000 g,purity≥95.00%,germination rate≥70.00%and germination potential≥60.00%;Ⅱ-class seeds with 1000-grain weight≥0.9500 g,purity≥90.00%,germination rate≥60.00%and germination potential≥50.00%;Ⅲ-class seeds with 1000-grain weight≥0.9000 g,purity≥85.00%,germination rate≥50.00%and germination potential≥40.00%;The water content of three grades of seed is≤7.50%.2.Study on the effects of planting density,fertilization and planting methods on the quality of Platycodon radix.（1）Planting density has a significant effect on the appearance of Platycodon radix.Under different planting densities,the root length,root crown diameter,middle root diameter,fresh weight and dry weight of Platycodon radix increase with the decrease of planting density,and the number of branches decreases with the decrease of planting density.The contents of water,total ash and alcohol extract of Platycodon radix under different planting densities all meet the requirements.The effects of planting density on the contents of six saponins in Platycodon radix are different.According to the results of principal component analysis,when the planting density is 12 cm×20 cm（27 800plants/667m²）,the quality of Platycodon radix is better.（2）There are some differences in appearance,alcohol extract and chemical composition content of Platycodon radix under different ratios of nitrogen,phosphorus and potassium fertilizer,but overall,the combination of nitrogen,phosphorus and potassium fertilizer can improve the appearance and chemical composition content of Platycodon radix,and the best performance is achieved when the ratio of nitrogen,phosphorus and potassium fertilizer is N2P2K2（N 16.68 kg/667m²,P₂O₅ 12.01kg/667m²,K₂O 9.34 kg/667m²）.Under different fertilizer ratios,the contents of water,total ash and alcohol extract of Platycodon radix all meet the requirements.Different farmyard manure has different effects on the appearance and chemical composition of Platycodon radix.Among them,when pig manure was applied,the diameter of root cap,the diameter of middle root and the dry rate of Platycodon radix were larger,and the number of branches was less.The contents of deapi-platycoside E,platycodin D₃ and platycodin D₂ were the highest when pig manure was applied.Under different farm manure treatments,the contents of water,total ash and alcohol extract of Platycodon radix met the requirements.Generally speaking,the quality of Platycodon radix is better when pig manure is applied.（3）The root length,root cap diameter and middle root diameter of Platycodon radix planted with plastic film increased,and the number of branches decreased.However,there are differences in the degree of increase of appearance traits between white film and black film.The contents of six saponins in Platycodon radix planted with white film were higher than those planted without plastic film.The contents of water,total ash and alcohol extract of Platycodon radix under different planting methods all meet the requirements.Generally speaking,the quality of Platycodon radix planted with white film is better.3.Study on the effect of harvesting and processing on the quality of Platycodon radix（1）During the harvesting period from September 9 to October 28,the root length and fresh weight of Platycodon radix changed more actively,while the diameter and dry weight changed less.The appearance index of Platycodon radix increased with the increase of growth years.The contents of six saponins in Platycodon radix showed a dynamic change process during the harvesting period,and the contents of saponins in three-year-old Platycodon radix were higher than those in two-year-old.According to the results of principal component analysis,the quality of three-year-old Platycodon radix is higher than that of two-year-old,and the quality of Platycodon radix is higher when it is harvested from October 7 to October 14.（2）Under different processing methods,the contents of water,total ash and alcohol extract of Platycodon radix met the relevant regulations.The contents of six saponins are obviously different under different processing methods.Generally speaking,the contents of deapi-platycoside E,platycoside E and platycodin D₃ are higher without peeling,while the contents of platycodin D₂,deapio platycodin D,and platycodin D are higher when peeling.Whether peeling or not has no obvious effect on the content of alcohol extract in Platycodon radix.The results of principal component analysis showed that the quality of Platycodon radix was the best when peeled and dried at 60℃.In this study,the optimal planting density of Platycodon radix in Tongliao,was27 800 plants/667m²,and the suitable plant spacing and row spacing were 12 cm×20cm.It is suggested that the best fertilization scheme for Platycodon radix in Tongliao area is N2P2K2,namely,N 16.68 kg/667m²,P₂O₅ 12.01 kg/667m²and K₂O 9.34kg/667m².Among different farmyard manure,the quality of medicinal materials is better when pig manure is applied.Among different planting methods,the quality of Platycodon radix planted with white film is better.It is suggested that the best harvesting period for planting Platycodon radix in Tongliao area is three years,and the suitable harvesting period is from early October to mid-October.Among different processing methods,the quality of Platycodon radix is the best when peeled and dried at 60℃.