Different Growth Years And Harvest Period Of Zizhou Astragalus And Its Quality And Yield Difference Analysis

Astragalus Radix,the dried root of Astragalus membranaceus(Fisch.)Bge.var.mongholicus Bge.Hsiao or Astragalus membranaceus(Fisch.)Bge.,is a very commonly used Chinese medicinal material.There is a saying that "Eight of the ten prescriptions require Astragalus Radix." Zizhou Asragalus is a new brand of Astragalus that has risen in recent years.Its unique geographical environment,special planting and processing technology have created excellent quality,and it is favored by the high-end market.The growth years and harvesting periods are the key factors to ensure the quality of Zizhou Astragalus.However,some people shorten their growth period or dig at any time driven by profits,resulting in a decline in product quality and the damage to the brand reputation of Zizhou Astragalus.Such problems can be solved by establishing standards about the growth years and harvest periods for Zizhou Astragalus of different qualities.The premise of establishing standards is to find out the identification characteristics of Astragalus with different growth years and harvesting periods and to clarify the influence of growth years and harvesting periods on the yield and quality of Zizhou Astragalus.In response to the above problems,the research materials in this project are Zizhou Astragalus with different growth years(1-6 years)and different harvesting periods(May-November).Objective:To establish the identification characteristics for the growth years and harvest periods of Zizhou Astragalus.To clarify the influence law of the growth years and harvest periods on the yield and quality of Zizhou Astragalus medicinal materials.Methods:Zizhou Astragalus samples with different growth years or harvest periods were detected with the methods of measuring plant morphological characteristics,tissue sections microscopic observation,electronic nose odor determination,etc.Then,the data was analyzed to establish the identification characteristics of its growth years and harvest periods.The yield was analyzed by the methods of measuring dry and fresh weight respectively.The content of flavonoids and astragaloside ? were determined by HPLC-PDA and HPLC-ELSD,and the total flavonoid content was confirmed by UV method,through which the effects of different growth years and harvesting periods on the yield and quality of Zizhou Astragalus medicinal materials were clarified.Results:1.The study of morphological characteristics of the above-ground organs showed that the tillers number of Zizhou Astragalus at the age of 1 to 2 was less than 3,the Zizhou Astragalus in the 1-year growth period would not bloom,and the flowering and fruiting rate of the Zizhou Astragalus in the 2-year growth period was less than 50%.While the tillers number of Zizhou Astragalus with a more than 3-years growth period was greater than or equal to 3,and its flowering and fruiting rate was above 90%.2.The study of morphological characteristics of the underground organs showed that the diameter of rhizomes of Zizhou Astragalus with a one-year growth period was less than 1.0 cm,and there were no features of epidermal decay and internal hollowness.The diameter of rhizomes of only a few Zizhou Astragalus with a two-year growth period could reach 1.0 cm,and the epidermal decay and internal hollowness appeared.Furthermore,the diameter of almost all Zizhou Astragalus with a growth period of 3 years and more could reach 1.0 cm,with epidermal decay and internal hollowness features.3.The results of the growth ring study indicated that the number of growth rings corresponding to the growth years could be observed on the cross-section of Zizhou Astragalus with lower growth years(1-4 years),while for those with higher growth years(4-5 years),the growth rings number could not be identified.When collecting materials,the roots with a length of 45 cm below the rhizome were uniformly selected as the growth period standards of this Astragalus.4.The results of electronic nose analysis showed that the electronic nose technology could not distinguish Zizhou Astragalus of the adjacent growth years,but it could distinguish the Zizhou Astragalus with greatly different growth years.5.The study results of effects of different growth years and harvesting periods on the yield and quality of Zizhou Astragalus showed that the total production of Astragalus tends to increase first and then flatten as the growth period increases,and it reached its peak in the fifth year of growth.As the harvest period progressed,the yield of Zizhou Astragalus showed an increasing trend,with the highest yield in autumn.Correlation analysis of the main component content and diameter of Zizhou Astragalus with different growth years and harvest periods showed that there was an extremely significant(P<0.01)negative correlation between the astragaloside ? content and diameter,and the isoflavone glucoside content and diameter had a significant(P<0.05)positive correlation.Among the Zizhou Astragalus harvested from May to November with diameters greater than 1 cm and a growing period of 3-6 years,the sample with the highest content of astragaloside ? was collected in June with a growing period of 6 years.The samples with the highest isoflavone glucoside and total flavonoid content were collected in May with a 6-year growth period.Conclusion:This thesis established identification methods for the growth years and harvest periods of Zizhou Astragalus,and found that the combination of multiple indicators is an effective means to identify the growth periods of Zizhou Astragalus.The effects of growth years on the yield and quality of Zizhou Astragalus were clarified,and it was found that sufficient growth years and suitable harvesting periods are important guarantees for the excellent quality of Zizhou Astragalus.It provides a basis for the development of the growth period and harvest period standards of Zizhou Astragalus.