Micropropagation and DNA Barcoding Studies in the Genus Scutellaria

Genus Scutellaria, commonly known as skullcaps, is a member of the Lamiaceae (mint) family of which some of species serve as an excellent source for secondary metabolites or phytochemicals. Increasing the production of medicinally and economically important plant species through micropropagation promotes in situ conservation by reducing effects of wild cropping, produces an ongoing supply of genetically identical plants, simplifies reproduction of recalcitrant species, promotes conservation of endangered species, and promotes plant improvement through genetic manipulation. Agrobacterium-mediated transformation of selected Scutellaria species was used to introduce AtMYB12, a transcription factor involved in the phenylpropanoid pathway. Upregulation of this pathway results in higher production of phytochemicals, thus yielding the selected species more valuable medicinally and economically. Because some of the species are rare, threatened or endangered, DNA barcoding has been used in this study for species identification based on nucleotide diversity of short DNA segments. With the DNA extracted from the germplasm collection of 21 species at Fort Valley State University, four candidate DNA barcode genes: the ribosomal RNA maturase gene (matK), the ribulose-1,4-bisphospate carboxylase/oxygenase gene (rbcL), the chloroplast intergenic spacer (psbA-trnH) and the ribosomal intergenic spacer (ITS) were amplified to discriminate between the Scutellaria species via polymerase chain reaction (PCR).The primers used to ensure proper identification were:rbcL, rbcL2, rbcL1-99, matK2.1-5-r, matK-3f1, psbA-trnH and ITS2. The amplicons verified by agarose gel electrophoresis were sent for sequencing and DNA sequences were uploaded to the Barcode of Life Data System (BOLD) and Basic Local Alignment Search Tool (BLAST) for analysis.