Characterization of Talinum triangulare (Jacq.) Willd. germplasm using molecular descriptors

• Morphological, biochemical and molecular characterization of T. triangulare germplasm
• Genetic diversity among accessions based on RAPD fingerprinting and DNA barcoding
• Species discrimination, identification and intra-specific phylogenetic relationship
• DNA sequencing of three chloroplast and one nuclear barcode as suggested by CBOL

Talinum triangulare is a medicinal herb known to have originated from tropical Africa and is now widely cultivated in the humid tropical countries. The characterization of plant germplasm using molecular descriptors aids in describing the genotypic traits of the plant T. triangulare. Ten different accessions of T. triangulare were collected from nine districts of Tamil Nadu. High quality genomic DNA was isolated from the different samples, checked for purity and quantified. The DNA samples were subjected to PCR amplification using RAPD markers and by DNA barcoding technique. RAPD fingerprints were generated for the 10 different accessions of T. triangulare for the first time. Ten random decamer primers resulted in 73.08% of polymorphism by producing a total of 78 fragments, of which, 57 bands were determined as polymorphic loci. Phylogenetic relationship and intra-specific variation among the samples were established by constructing a dendrogram based on Jaccard's coefficient. DNA barcoding studies included the amplification of chloroplast large subunit of ribulose-bisphosphate carboxylase (rbcL), trnH-psbA intergenic spacer (trnH-psbA), maturase K (matK) and nuclear internal transcribed spacer (ITS). The amplicons were gel eluted, sequenced and checked for homology by using the BLAST tool. However, no variation was detected among the samples after sequencing, proving that the accessions were identical at the genetic level.