DNA barcoding as a valuable molecular tool for the certification of planting materials in bamboo

Abstract

DNA barcodes developed for selected commercially important bamboo species can be utilized for the certification of planting stock in bamboo nurseries in absence of discriminatory features at the juvenile stage. Planting materials such as micropropagated plantlets, rhizome transplants and culm cuttings, generated at nursery level are directly procured for establishment of commercial plantations without any further verification. Very often misidentification and mixing up occur at nursery level and the error is not discovered until several years have passed. The present study evaluated the potentiality of seven Consortium for Barcode of Life (CBOL) recommended standard DNA barcode regions in commercially important bamboo species of India. Among the analyzed barcode regions, multiple sequence alignment (MSA) of psbA-trnH barcode region showed species-specific nucleotide differences in the studied bamboo taxa. The major nucleotide changes observed were transitions/transversions as well as insertions/deletions of nucleotides. Even though species-specific mononucleotide differences could be identified for most of the studied bamboo taxa, a small amount of sequence similarities were found in some of the Dendrocalamus and Bambusa species, which were grouped together in tree-based analysis. In subtribe Melocanninae, Ochlandra travancorica, Melocanna baccifera and M. clarkei showed unique species-specific psbA-trnH barcodes. Similarly, in the genus Oxytenanthera, unique species-specific psbA-trnH barcodes were obtained for O. monadelpha and O. parvifolia. Thus psbA-trnH barcode region generated distinct species-specific barcodes for commercial bamboo species in genera Bambusa, Dendrocalamus, Melocanna, Oxytenanthera as well as Ochlandra. Any national certification agency set up for the purpose can utilize psbA-trnH DNA barcode region to tag species identity and to establish the authenticity of multiplied planting materials in bamboos.