Molecular identification of genus Scylla (Decapoda: Portunidae) based on DNA barcoding and polymerase chain reaction

摘要

In this study, we first examined the utility of COI sequences as DNA barcoding for identification of genus Scylla, which includes four species: Scylla paramamosain, Scylla serrata, Scylla tranquebarica and Scylla olivacea. The mean intraspecific Kimura 2-parameter distances were 0.003 for S. paramamosain, 0.014 for S. serrata, 0.017 for S. olivacea and 0.006 for S. tranquebarica. The interspecific K2P distances were higher than the intraspecific distances: the minimum interspecific distance (0.092) was between S. paramamosain and S. tranquebarica while the maximum interspecific distance (0.196) was between S. paramamosain and S. olivacea. No overlap was found between intraspecific and interspecific distances, suggesting the existence of a distinct barcoding gap. The maximum-likelihood (ML) phylogenetic tree consisted of four distinct clusters, each containing individuals from one species only. Furthermore, a molecular species identification method was developed successfully, by which these four species could be identified rapidly and effectively from each other though a PCR reaction. (C) 2011 Elsevier Ltd. All rights reserved.