台灣地區白茅核糖體DNA內轉錄間隔區異質性之研究

The Heterogeneity of the Internal Transcribed Spacers (ITS) of rDNAs in Imperata cylindrica in Taiwan

利用聚合酶連鎖反應可將45株生長於台灣地區之白茅的核糖體DNA（rDNA）內轉錄間隔區（internal transcribed spacer，ITS）複製出來，其長度除一樣本為702 bp外，其餘樣本皆為692 bp。再利用10種限酶進一步偵測不同白茅樣本之ITS序列，發現台灣白茅族群之ITS區成（含ITS1，5.8S rRNA基因及ITS2）之序列異質性相當高，甚致個體內出現不同類型的ITS序列之情形亦相當普遍。就整個台灣白茅族群而言，在ITS1及ITS2序列方面，共偵測到8種不同類型之序列。在5.8S rRNA基因方面，共偵測到5種不同類型。因此，由本研究發現台灣地區白茅族群之ITS區域具有很高之異質度。

Ribosomal DNA for internal transcribed spacers ITS, ITS1, 5.8S rRNA gene, ITS2 and the adjoining regions of the 17S and 25S rRNA genes were obtained from 45 individuals of Imperata cylindrica (Cogongrass) in Taiwan via PCR amplification. The length of each PCR product was 692 bp, except for one sample (about 702 bp). All ITS DNA fragments were digested with EcoRV, CfoI, BanI, HaeIII, MspI, HinfI, BstOI, Sau961, StyI and Eco109I, respectively. The ITS, including ITS1, 5.8S rRNA gene and ITS2, were very heterogeneous within an individual of Cogongrass in Taiwan. Of 45 individuals of Cogongrass in Taiwan, the ITS1 and ITS2 regions showed at least eight type variants, and 5.8S rRNA gene showed at least five type variants among Cogongrass population in Taiwan based on PCR-amplificd RFLP. In conclusion, the ITS repeat sequences from Cogongrass in Taiwan was very high heterogeneous.