Morphological characteristics of leaves and DNA barcoding for identification of Mentha haplocalyx and its related species / 中草药

ABSTRACT

Objective: The morphological characteristics of plants and the application of ITS2 and psbA-trnH sequences in the identification of Mentha haplocalyx and its related species were discussed in order to provide references for the identification of M. haplocalyx and its related species. Methods: The morphological characteristics such as the shape of leaf and leaf edge, villous density and glandular scale density of M. haplocalyx and its related species were observed. Alignment was performed to compare ITS2 and psbA-trnH sequences of the tested materials. The data were processed and analyzed by means of comparing the morphological characteristics of plants, analyzing the DNA barcode sequences, calculating the genetic distance, and constructing NJ trees. Results: The NJ trees were constructed according to the morphological characteristics of plants combined with ITS2 and psbA-trnH sequences, which showed that M. arvensis was closely related to Satureja Hortensis, Salvia miltiorrhiza was closely related to Perilla frutescens, Mentha piperita was closely related to the Monarda didyma and Agastache rugosa was closely related to Nepeta cataria. This method could distinguish M. haplocalyx from its related species. Conclusion: ITS2 and psbA-trnH sequences can be used as DNA barcode of M. haplocalyx and its related species, and the combination with morphological characters of leaves is better for the identification.