Premium
Species discrimination in S isyrinchium ( I ridaceae): assessment of DNA barcodes in a taxonomically challenging genus
Author(s) -
S. Alves Tiago L.,
Chauveau Olivier,
Eggers Lilian,
SouzaChies Tatiana T.
Publication year - 2014
Publication title -
molecular ecology resources
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.96
H-Index - 136
eISSN - 1755-0998
pISSN - 1755-098X
DOI - 10.1111/1755-0998.12182
Subject(s) - dna barcoding , biology , barcode , tribe , evolutionary biology , genus , taxonomic rank , zoology , botany , taxon , sociology , anthropology , computer science , operating system
DNA barcoding aims to develop an efficient tool for species identification based on short and standardized DNA sequences. In this study, the DNA barcode paradigm was tested among the genera of the tribe S isyrinchieae ( I ridoideae). S isyrinchium , with more than 77% of the species richness in the tribe, is a taxonomically complex genus. A total of 185 samples belonging to 98 species of S isyrinchium , O lsynium , O rthrosanthus and S olenomelus were tested using mat K , trn H ‐ psbA and internal transcribed spacer ( ITS ). Candidate DNA barcodes were analysed either as single markers or in combination. Detection of a barcoding gap, similarity‐based methods and tree‐based analyses were used to assess the discrimination efficiency of DNA barcodes. The levels of species identification obtained from plastid barcodes were low and ranged from 17.35% to 20.41% for mat K and 5.11% to 7.14% for trn H ‐psb A . The ITS provided better results with 30.61–38.78% of species identified. The analyses of the combined data sets did not result in a significant improvement in the discrimination rate. Among the tree‐based methods, the best taxonomic resolution was obtained with B ayesian inference, particularly when the three data sets were combined. The study illustrates the difficulties for DNA barcoding to identify species in evolutionary complex lineages. Plastid markers are not recommended for barcoding S isyrinchium due to the low discrimination power observed. ITS gave better results and may be used as a starting point for species identification.