| 摘要: | 山螞蝗屬植物屬於豆科，全世界約有350種，主要分布於熱帶和亞熱帶區域，其在醫療方面具重要價值。
台灣的山螞蝗屬植物有18種，大多生長在中低海拔地區，除了作綠肥及牧草使用外，亦有某些被當藥用，但在使用上卻常有混用或誤用的情形。
為改善此情況，本研究透過不同方法對10種山螞蝗屬植物加以鑑定。首先，以感官法及掃描式電子顯微鏡確定外部形態。其次，進行組織切片，觀察並比較內部構造異同，同時建立標準生藥組織圖譜。最後，本研究利用聚合酶鏈鎖反應 (polymerase chain reaction；PCR) ，將核糖體DNA的內轉錄間隔 (internal transcribed spacer；ITS) 區域放大並定序。
研究結果顯示，許多外形特徵及組織特徵都可作為鑑定上之依據。另外，這些植物的ITS區域長度為585-620bp，此區包含ITS1、5.8S rRNA gene及ITS2三部分，其長度分別為194-237bp、164bp及210-227bp，G+C 百分比分別為61.8-67.1%、52.4或53.0%及58.3-65.3%。進一步分析發現，各物種間ITS區域之序列相似度為78-98%。本研究亦歸納出其序列保留區形式為：GGCGC-(5 to 6n)- GCGCCAAGGAX (X表A、T或G) 。
利用上述方法，能有效鑑別這些植物，為其深入研究、臨床應用或生藥資源開發，提供一簡單、方便而可信的鑑定參考依據。
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. |
