[Determination of mineral elements in different part of Astragalus membranaceus(Fisch.) by FAAS].

Having digested the root and shoot of Astragalus membranaceus (Fisch.) with the mixture of nitric acid and perchloride acid (4 : 1) under the condition of the bolling point and the normal pressure, the contents of the five mineral elements necessary to humanity, potassium, copper, zinc, iron and manganese in root and shoot of Astragalus membranaceus (Fisch.) were determined by flame atomic absorption spectroscopy (FAAS), and the results were analyzed in statistics. The correlative coefficient of the standard curve in this method is 0.997 3-0.999 9, the recovery of standard addition was 92.88%-109.25% and the relative standard deviation (RSD, n = 5) was 0.393 5%-3.175 2%. The method is simple and the results were accurate and reliable. The contents of K, Fe, Zn, Mn, Cu in the root and shoot of Astragalus membranaceus (Fisch.) were compared. The results showed that the sequence of the content of metal elements is as follows in all samples: K > Fe > Zn > Mn > Cu. However, the distribution of elements in shoot and root is not uniform, and the content of Fe, Zn and Cu in root is richer than in shoot. There are abundant Fe, Zn and Cu in root, for example, the content of Fe in root is 1.54 times that in shoot. In addition, there are also abundant mineral elements in the shoot, especially in K and Mn, for example, the content of K in shoot is 1.63 times that in root. The contents of K, Fe, Zn, Mn and Cu in shoot are in agreement with the medical effects of Astragalus membranaceus (Fisch.). The results should provide useful data for investigating the distribution of mineral element in Astragalus membranaceu body and the correlation between the mineral element content and the effect of medicine in Astragalus membranaceus (Fisch.).

[Study on difference of biological characteristics and resistance to powdery mildew of different Astragalus populations].

OBJECTIVE: To study difference among populations which belong to Astragalus membranaceus and A. membranaceus var. mongholicus on morphology, habit, characteristics of physiology and resistance to powdery mildew, and classify them in order to provide theoretical basis for breeding and improving varieties. METHOD: Morphology, habits, isozyme and soluble protein electrophoretograms were compared among the populations. They were categorized by cluster analysis based on those electrophoretograms. Different ability of resistance to powdery mildew was also studied through comparing disease indices among six populations. RESULT: The results showed A. membranaceus var. mongholicus was distinctly different from A. membranaceus. There was a special type in colonies of A. membranaceus, which showed hairy upper epidermis of leaflets and later florescence. CONCLUSION: Astragalus for medicine could be categorized in three types A. membranaceus var. mongholicus, A. membranaceus early florescence type and A. membranaceus late florescence type. Among them A. membranaceus var. mongholicus is most resistant to powdery mildew, while A. membranaceus is easily infected, and the early florescence type is even more easily infected.