DNA barcoding supports existence of morphospecies complex in endemic bamboo genus Ochlandra Thwaites of the Western Ghats, India

Abstract

Ochlandra Thwaites, an economically exploited bamboo genus of the Western Ghats of India is severely affected by unsustainable extraction, natural habitat destruction and endangerment of species resources. This taxonomically challenging genus consists of a genetic mixture of 10 related polyploid species that are difficult to define and classify using traditional morphology. The present study investigated the probability of DNA barcoding using seven standard barcode regions recommended by CBOL as a supplementary tool to define true species boundaries. Distance (MEGA v.6.0) and sequence similarity (TaxonDNA) based approaches highlighted the discriminatory power of psbA-trnH intergenic spacer barcode region, but did not support true species entities. Neighbour-joining and Bayesian inference trees supported the existence of morphospecies complex in seven species of the genus owing to weak reproductive barriers amongnaturally coexisting species. Morphological affinities existing within genus might have stemmed from natural interspecific hybridization events and consequent reticulate evolution in morphospecies complex of genus Ochlandra.