Abstract

Molecular approaches are now being developed to provide a more rapid and objective identification compared to traditional phenotypic methods. Nuclear ribosomal DNA (nrDNA) targets, especially internal transcribed spacer 1 and 2 (ITS1 and ITS2), have been widely used for molecular identification of some plants and fungi. We therefore conducted an investigation in the identification of the fifth medically important Zanthoxylum schinifolium ecotypes using the common primers of the ITS region. About 620 bp fragments were obtained and the sequences of the polymerase chain reaction (PCR) products were tested. The sequence length, G+C content (%), DNA alignment and pariwise nucleotide comparisons demonstrated 98.8 to 100% sequence identities in the total ITS region, 98.3 to 100% identities in the ITS1 region and 99.5 to 100% in the ITS2 region. Comparative analysis using GenBank reference data showed that the exclusive reported data showed 100% identities with BEMR, CWDO, HCDC, JDGG and GJGD in the ITS1 region and 100% identities with thirteen ecotypes except BEMR and GRDG in the ITS2 region. The fifth different ecotypes were classified into five groups and the identification of medically important Z. schinifolium was highly improved due to the augmentation of our current ITS sequences.

Key words: Zanthoxylum schinifolium, molecular identification, phylogenetic relationship, ribosomal DNA, ITS1, ITS2.

Abbreviation

nrDNA, Nuclear ribosomal DNA; ITS, internal transcribed spacer;PCR, polymerase chain reaction; BLAST, basic local alignment search tool; NCBI,National Center for Biotechnology Information; SSR, simple sequence repeat.