Cloning and analysis of rDNA ITS sequences from 11 medicinal plants in Viola L / 中草药

ABSTRACT

Objective: To provide molecular evidences for identification of medicinal plants in Viola L. by determining and analyzing the rDNA internal transcribed spacers (ITS) sequences of 11 species in Viola L. Methods: ITS sequences were isolated using PCR amplification, and sequence analysis, evaluation of genetic distance as well as construction of phylogenetic tree were conducted by bioinformatics software. Results: Full ITS sequences of 11 plants in Viola L. were varied from 612 to 638 bp in length. The lengths of ITS1 and ITS2 were 251-265 bp and 198-211 bp, respectively, while 5.8 S sequences were more conserved with identical length of 163 bp. Parsimony information sites of ITS1, ITS2, and 5.8 S were 50, 23, and 3, respectively. Genetic distance among 11 species in Viola L. varied from 0.025 to 0.137, and the greatest genetic distances were observed between V. grypoceras and V. diffusa var. brevibarbata, indicating their relative distinct relationship, and the smallest existed between V. diffusa and V. acuminata, revealing their closest relationship. Conclusion: ITS sequences of 11 medicinal plants in Viola L. were obtained with a result of rich information sites, which provideds a foundation for molecular identification.