Studies on Its Sequences and Systematic Classification of Osmanthus

In this article, ITS sequences of 20 species in Osmanthus were cloned and researched. It was found that length of ITS sequences ranged from 614bp to 619bp, in which ITS-1 is obviously longer than ITS-2, 5.8S of 20 species is composed of 163bp, and the percentage of G+C in ITS sequence of 20 species is 54.24%-64.56%. Alignment between ITS sequences from 20 species of Osmanthus was performed, and discovered that the similarity coefficient between 20 species is 86.1%-99.7%, the minimum exists between O.suavi and O.attenuatus, the similarity coefficient between O.urceolatus and O.cooperi is the maximum. Furthermore, there are 198 mutation sites and 97 information sites in ITS sequences, respectively 31.53% and 15.45%, and the content of information sites in ITS-2 is more than that in ITS-1. In addition, three MP trees were respectively constructed based on ITS sequences, ITS-1 sequences and ITS-2 sequences, 20 species of Osmanthus were divided into three groups, O.americanus belonged to the first group, O.yunnanensis and O.attenuatus were clustered one group, and the other 17 species belonged to the third group, which is partly consistent with the viewpoint of traditional classification about Osmanthus.