基于ITS2和psbA-trnH序列鉴别巴戟天及其3种近缘植物

Identification of Morinda officinalis and Its Three Close Plant Species Based on ITS2 and psbA-trnH

基于ITS2和psbA-trnH序列鉴别巴戟天及其3种近缘植物。对巴戟天及其3种近缘植物的ITS2和psbA-trnH序列进行PCR扩增和测序,运用遗传距离分析、DNA Barcoding Gap和系统发育(NJ)树3种方法对其进行鉴别。结果,巴戟天及其3种近缘植物的ITS2序列长度为237bp,GC含量为70.3%,保守率为86.08%,变异率为13.92%,ITS2序列上种间变异大于种内变异,存在较显著的DNA Barcoding Gap,其NJ树能准确鉴别出全部供试物种。巴戟天及其3种近缘植物的psbA-trnH序列长度为290bp,GC含量为20.2%,保守率为53.10%,变异率为46.55%,psbA-trnH序列上种间变异大于种内变异,无明显的DNA Barcoding Gap,其NJ树仅能准确鉴别出海滨木巴戟和羊角藤。ITS2序列的物种鉴定能力优于psbA-trnH序列。因此,基于ITS2和psbA-trnH序列能成功鉴别巴戟天及其3种近缘植物。

To identify Morinda officinalis and its three close related plant species based on ITS2 and psbA-trnH, the ITS2 and psbA-trnH of Morinda officinalis and its three close related plant species were amplified by PCR and sequenced. Genetic distance analysis, DNA Barcoding Gap and NJ tree were used to identify the above species. The results showed that the length of ITS2 was 237bp, the GC content was 70.3%, the conserved rate was 86.08%, and the mutation rate was 13.92%. The interspecific variation based on ITS2 was greater than the intraspecific variation, and there was significant DNA Barcoding Gap. The NJ tree based on ITS2 can accurately identify all the experimental species. The length ofpsbA-trnH was 290bp, the GC content was 20.2%, the conserved rate was 53.10%, and the mutation rate was 46.55%. The interspecies variation based on psbA-trnH was greater than the intraspecies variation, and there was no obvious DNA Barcoding Gap. PsbA-trnH can only accurately identify two species. The species identification ability of ITS2 is better than psbA-trnH, which can accurately identify Morinda otficinalis and its three closely related plants. In conclusion, based on the ITS2 and psbA-trnH sequences, Morinda officinalis and its three closely related plants can be successfully identified.