Identification of Desmodium Species in Taiwan (Ⅰ)

• Main Authors: Yi-Jen Lin, 林怡仁
• Other Authors: 邱泰惠
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/30608258686335330838

碩士 === 中國醫藥大學 === 藥學系碩士班 === 97 === The genus Desmodium belongs to the family Leguminosae. There are about 350 species in the world and mainly distribute in the tropical and subtropical zone. They have important value in medicine. There are 18 species of the genus Desmodium in Taiwan. They mostly grow in medium and low altitude areas. Besides being used for green manure and forage, some of them can be used as herbal medicine. However, the situation of mixed or missed use is very common. To improve the condition, the study was to identify 10 species of the genus Desmodium by different methods. First, confirming the morphological appearances by sense and scanning electron microscope observation. Second, sectioning them to find and compare the histological characteristics. The standard maps of pharmacognostical histology were also set up at the same time. Finally, polymerase chain reaction (PCR) techniques were used to amplify internal transcribed spacer (ITS) regions of ribosomal DNA and then the sequences were recognized. The study results showed that many morphological and histological features could be as bases of identification. Moreover, the length of ITS regions of these species was 585-620bp, including 194-237bp of ITS1, 164bp of 5.8S rRNA gene, and 210-227bp of ITS2. The G+C contents of ITS1, 5.8S rRNA gene and ITS2 were 61.8-67.1%, 52.4 or 53.0%, and 58.3-65.3%. Further analysis revealed that the sequence similarity of ITS regions between these species was 78-98%. The form of their conserved sequences : GGCGC-(5 to 6n)- GCGCCAAGGAX (X is A, T, or G) was also generalized in the study. It could effectively identify these species by the methods and provided a simple, convenient, and trusty reference of identification for further studies, clinical application or pharmacognostical development.