Developmental anatomy of anomalous structure and classification of commercial specifications and grades of the Astragalus membranaceus var. mongholicus.

The Daodi herb, Huangqi from Shanxi, is derived from the root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao. Huangqi was divided into different commercial specifications and grades in producing area according to macroscopic features. Developmental anatomy of anomalous structure of the perennial fresh main root of A. membranaceus var. mongholicus was investigated using conventional paraffin section to explore the relationship between anomalous structure and classification of commercial specifications and grades of Huangqi. The results of developmental anatomy showed that parenchyma cells in secondary phloem and secondary xylem of the perennial fresh main root regained meristematic ability, and resulted in anomalous structure. Several layers of additional periderm could sometimes be found in the secondary phloem near the initial periderm, which was called rhytidome. Additional periderm could sometimes be observed in the center of secondary xylem, which was described as "rotten heart." The area of rhytidome and "rotten heart" increased gradually with increasing age. The results of different commercial specifications and grades of Huangqi revealed rhytidome and "rotten heart" mainly existed in Ge-Da-Tou, Er-Dao-Tou, Hong-Lan-Qi, Special Class, First Class, and Second Class. The additional periderm in secondary phloem of Ge-Da-Tou, Er-Dao-Tou, Hong-Lan-Qi, and Special Class could reach five layers; however, that of First Class and Second Class was three layers at most. In summary, this study demonstrated the rules of the development of rhytidome and "rotten heart" in A. membranaceus var. mongholicus. The relationship between anomalous structure and different commercial specifications and grades of Daodi herb Huangqi, was clarified. RESEARCH HIGHLIGHTS: The rhytidome and the development of "rotten heart" have not been reported in Astragalus membranaceus var. mongholicus. At present article, we demonstrated the developmental anatomy of the rhytidome and "rotten heart" existed in the secondary phloem and secondary xylem of the root of A. membranaceus var. mongholicus respectively. The rhytidome and "rotten heart" is different among six commercial specifications and grades of Huangqi.

[Induction and identification of polyploid of Astragalus membranaceus var. mongholicus].

In this article, improved agar painting method, with semi-solid of 0.2% colchicine and 0.1% agar, was adopted to treat apical buds of Astragalus membranaceus var. mongholicus (Bge.) Hsiao seedlings. Obtained plants were proved to be tetraploids by identification of biological characteristics and chromosome numbers.

Microscopic research on a multi-source traditional Chinese medicine, Astragali Radix.

Astragali Radix is a widely and commonly used Chinese herbal medicine, which is derived from roots of Astragalus membranaceus var. mongholicus and Astragalus membranaceus. To find a quick and reliable method of distinguishing these two species of Astragali Radix and of determining the age of a sample, microscopic characteristics of the two species were compared using light microscopy. The results showed that the microscopic characteristics, such as number of layers of phellem, continuing lignified xylem bundles within spring wood and lignified parenchyma cells in the central part of the xylem could be used for the differentiation of the root of A. membranaceus from the root of A. membranaceus var. mongholicus. Growth rings (annual rings) were found for the first time in the roots of both species, and could determine the age of a sample. For the first time, radial fibers in both species of Astragali Radix and pipette-shaped fibers in A. membranaceus var. mongholicus were found. The structure of "rotten heart" cork tissue (decayed central xylem) and tubular cork tissue was carefully studied, and the arranged order of tissues in both "rotten heart" and tubular cork tissues is phelloderm and phellem from outside to inside, which is contrary to that in the periderm.