Comparison Of Different Soil Conditions On Growth And Quality Of Platycodon Grandiflorus In Tianjin Area

With strong ability of stress tolerance of Platycodon grandiflorus as experimental materials to mainly study flowering phenology,growth period of growth,photosynthetic characteristics and secondary metabolites,the roots of vegetative organs yield and quality characteristics of Platycodon grandiflorus which cultivated in Tianjin area with three kinds of different soil conditions using the method of field investigation and laboratory test method.This experiment synthesize the action characteristics of ecological factors in experimental field to evaluate the effects of different soil conditions,especially moderate and mild saline soil,on the growth and quality of Platycodon grandiflorus.The purpose of this study is to provide experimental basis for planting Platycodon grandiflorus in the area of similar climate and soil conditions in Tianjin.The main results are summarized as follows:(1)Three experimental fields soil ecological factors characteristics:climate characteristics test of annual mean temperature in Jizhou District experimental field is the highest,the average minimum temperature in Jizhou district experimental field.Soil nutrient characteristics of bulk density in Xiqing District No.2 experimental field(sandy loam)was the largest.Total porosity,aeration porosity and water holding porosity,soil organic matter content of Jizhou District experimental field(more gravel clay loam)was significantly higher than that of Xiqing District No.1(clay loam)and No.2 experimental fields.There are many nutrient elements for plants to use in the experimental site,and the nutrients are suitable.(2)The duration of flowering period of Platycodon grandiflorus in three experimental fields was slightly different.The longest flowering of Platycodon grandiflorus for 106 days in Jizhou District experimental field and the earliest flowering period;Xiqing District No.2 of The shortest flowering of Platycodon grandiflorus for 85 days and the latest flowering period.(3)There were differences in growth traits during the growth period of Platycodon grandiflorus in three experimental fields.The growth of Jizhou District experimental field was significantly better than that of Xiqing No.1 and No.2 experimental fields,the majority of plant height in 35.1～45.0cm,very few can reach more than 60.0cm;the stem diameter in 6.1～9.0mm;most of stem leaves are in 12～17,the external form is stable;the average leaf length,leaf width,leaf area 54.11mm,27.45mm 10.40cm~2,wide leaf hypertrophy,stress resistant ability;leaf length width ratio according to the biological characteristics of leaf.The average root length,root diameter,root volume and root shoot ratio reached the maximum level of 11.69cm,22.9mm,22.5cm~3 and 1.47,the number of lateral roots was the least,and the root activity was stronger.(4)The content of pigment in leaves of Platycodon grandiflorus is the highest in Jizhou District experimental fields,chlorophyll and carotenoid content of up to 1.278mg/g and 0.415mg/g.The study on Photosynthetic Characteristics of leaves of Platycodon grandiflorus in three experimental fields showed the common influence of photosynthetic physiology and environmental factors.Among them,photosynthetically active radiation was the dominant factor,and net photosynthetic rate was positively correlated with transpiration rate and stomatal conductance.In August,Jizhou District experimental fields of water use efficiency showed the strongest response,strong ability of drought stress.In September,Xiqing District No.2 experimental field of the stomatal limit value was the largest,indicating that the stomatal opening of the leaves was low.(5)The physiological indexes of Platycodon grandiflorus in the three experimental fields were also slightly different.The average malondialdehyde content of Platycodon grandiflorus in Jizhou District experimental field for a minimum of 0.0032 mol/g,membrane system of stress damage minimum.The content of the average soluble sugar and soluble protein was slightly lower than that in Xiqing District No.2 experimental field were 0.0248%and 0.116mg/g.(6)There were also differences in the yield,the content and quality of the nutritive organs in the root of Platycodon grandiflorus in the three experimental fields.The average root weight,average biomass,average 667m~2yield and average drying rate of nutrient organs in the root of the Jizhou District experimental field were measured for a maxium of 38g,2.23kg,1485.19kg and 43.36%.The content of saponins D of Platycodon grandiflorus was also 1.18%,and the content of water and alcohol soluble extract was in accordance with the Chinese Pharmacopoeia(2015 Edition).The quality of Platycodon grandiflorus in three experimental fields met the standard of drug use.(7)Orthogonal design experiment on Ultrasonic Extraction Technology of Platycodon grandiflorus Jizhou District experimental field secondary metabolite and active ingredients were studied.The results show that the dominant factor is the ratio of material to liquid affect the content,and the combined process in their respective optimal extraction,optimal total flavonoids and saponins content of 2.164% and 1.617%.