Yu Kun-Zi, Liu Jing, Guo Bao-Lin, Zhao Zhong-Zhen, Hong Hao, Chen Hu-Biao, Cai Shao-Qing
School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, People's Republic of China.
J Nat Med. 2014 Apr;68(2):340-50. doi: 10.1007/s11418-013-0802-z. Epub 2013 Oct 2.
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.
黄芪是一种广泛且常用的中药材，来源于蒙古黄芪和膜荚黄芪的根。为了找到一种快速可靠的方法来区分这两种黄芪并确定样品的年龄，利用光学显微镜比较了这两种黄芪的微观特征。结果表明，木栓层层数、春材中连续木质化的维管束以及木质部中部木质化的薄壁细胞等微观特征可用于区分膜荚黄芪的根与蒙古黄芪的根。首次在这两种黄芪的根中发现了生长轮（年轮），并可据此确定样品的年龄。首次在两种黄芪中发现了径向纤维，在蒙古黄芪中发现了吸管状纤维。对“黑心”栓组织（腐烂的中央木质部）和管状栓组织的结构进行了仔细研究，“黑心”和管状栓组织中组织的排列顺序均为由外向内为栓内层和木栓层，这与周皮中的排列顺序相反。
