中文摘要：

以蜈蚣衣属、黑蜈蚣衣属地衣样品为材料,结合GenBank中相关数据,对地衣型真菌核糖体小亚基DNA上的Ⅰ型内含子分布模式进行归纳,并探讨了其在地衣型真菌系统发育研究中的应用。结果表明在地衣型真菌核糖体小亚基DNA上存在多个Ⅰ型内含子插入位点,通过二级结构分析给出了天然状态下Ⅰ型内含子发生转座的证据。分析显示,Ⅰ型内含子作为分子标记,只适合用于种下单位的系统发育研究中。

英文摘要：

Group I introns in SSU（Small Subunit） rDNA of lichen forming fungi and their distribution modes were analyzed in this study.The data were obtained from eight species of the lichen genera Physcia and Phaeophyscia with some sequences retrieved from GenBank.Our result indicates that there are multiple group I introns insertion sites in SSU rDNA of lichen forming fungi,and their secondary structures gives the evidences of transposition when group I introns are in its nature states.Our result also demonstrates that group I introns are only suitable for the phylogenetic analysis at infraspecific levels.