IDENTIFICATION OF GYMNEMA SPECIES BY RANDOM AMPLIFIED POLYMORPHIC DNA TECHNIQUE AND CHLOROPLAST trnK GENE

摘要

Gymnema is one of the important anti-diabetic medicinal plants used from ancient times and is commonly known as ‘sugar killer’. Most of its species have been used in many applications in Indian traditional medicine. Nevertheless, their efficiency is critically dependent on the use of the correct material. The sharing of similar vernacular name and morphological features make confusion in the usage of Gymnema species. In the present study, Gymnema sp. were identified through random amplified polymorphic DNA (RAPD) technique and species specific markers were generated for easy identification of G. elegans, G. montanum and G. sylvestre. Using the RAPD techniques of 3 species specific markers for G. sylvestre, 7 markers for G. elegans and 4 markers for G. montanum had been generated. Highest genetic identity was found between G. sylvestre and G. montanum and highest genetic distance was found between G. sylvestre and G. elegans. Further, DNA barcode was developed by sequencing chloroplast partial trnK DNA of these three species. No significant variation was found in partial trnK gene sequences between Gymnema species. But these sequences can efficiently differentiate the Gymnema and Mandevilla species. In-silico sequence–restriction fragment length polymorphism (RFLP) analysis revealed three fragments measuring G. sylvestre - 204, G. elegans - 174, and G. montanum - 168 bp Gymnema species. The present study concluded that RAPD markers were highly efficient for species detection than the partial trnK gene sequences. This could be used to confirm the Gymnema sp. identities and to ensure their safe application in pharmaceuticals.