Diversity of green and red macroalgee distributed in indian west-coast using morphometry and DNA barcoding
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Date
2013
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Publisher
Central University of Punjab
Abstract
Modern algal systematists exploit genetic tools for molecular assisted alpha
taxonomy and DNA barcoding is one such molecular tool that relies on the use of a
standardized DNA region as a tag for rapid and accurate species identification. In this
study Nuclear Internal Transcribed Spacer (ITS) was used as a marker for
identification and phylogenetic analysis of marine green and red macroalgae in
Indian subcontinent. Using Bayesian Inference for phylogenetic reconstruction with
T3P model of molecular evolution and gamma distribution (T3P+G) using ITS dataset
revealed that the bloom forming Ulva intestinalis found in west coast of Indian
subcontinent showed strong endemism, supporting the view that that the genus Ulva
encompasses a number of endemic cryptic species in addition to cosmopolitan
species. Although there were two morphotypes present in Indian isolates, they
constituted a single clade with robust Bayesian Posterior Probability support,
confirming conspecificity of these morphotypes. Our results also indicate latitudinal
gradients in the distribution of tubular Ulva, with a clade encompassing all nontropical
isolates. Higher genetic heterogeneity of tropical isolates as evidenced by
highest within-group T3P (Tamura-3-Parameter) distances comparing with that of
non-tropical isolates is suggestive of tropics being the geographic origin of these
species. While U. compressa and U. intestinalis were monophyletic within nontropical
superclade, these morphotypes were polyphyletic within the tropical clade.
Due to the polyphyly of currently accepted morphospecies concept and formation of
distinct phylogenetic clade among Indian isolates forces us to propose a new bloom
forming species of Ulva paschima. Further molecular assessment of invasive
Carrageenophyte Kappaphycus alvarezii using ITS-1 region showed affinity to
phylogenetic clade of mixed geographical origin confirming that the species was
introduced in the subcontinent by human intervention. Surprising result of our study
was an endophytic green algae Ulvella leptochaete that was found growing inside
Caldophora glomerata, a first report of its kind from India.
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Keywords
Macroalgae, DNA barcoding, nrITS region, Phylogram, Chlorophyta
Citation
Aijaz Ahmad John (2013) Diversity of green and red macroalgee distributed in indian west-coast using morphometry and DNA barcoding.