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Abstract Because of the detrimental effects of terrestrial invasive plant species (TIPS) on native species, ecosystems, public health, and the economy, many countries have been actively looking for strategies to prevent the introduction and minimize the spread of TIPS. Fast and accurate detection of TIPS is essential to achieving these goals. Conventionally, invasive species monitoring has relied on morphological attributes. Recently, DNA‐based species identification (i.e., DNA barcoding) has become more attractive. To investigate whether DNA barcoding can aid in the detection and management of TIPS, we visited multiple nature areas in Southwest Michigan and collected a small piece of leaf tissue from 91 representative terrestrial plant species, most of which are invasive. We extracted DNA from the leaf samples, amplified four genomic loci (ITS,rbcL,matK, andtrnH‐psbA) with PCR, and then purified and sequenced the PCR products. After careful examination of the sequencing data, we were able to identify reliable DNA barcode regions for most species and had an average PCR‐and‐sequencing success rate of 87.9%. We found that the species discrimination rate of a DNA barcode region is inversely related to the ease of PCR amplification and sequencing. Compared withrbcLandmatK, ITS andtrnH‐psbAhave better species discrimination rates (80.6% and 63.2%, respectively). When ITS andtrnH‐psbAare simultaneously used, the species discrimination rate increases to 97.1%. The high species/genus/family discrimination rates of DNA barcoding indicate that DNA barcoding can be successfully employed in TIPS identification. Further increases in the number of DNA barcode regions show little or no additional increases in the species discrimination rate, suggesting that dual‐barcode approaches (e.g., ITS + trnH‐psbA) might be the efficient and cost‐effective method in DNA‐based TIPS identification. Close inspection of nucleotide sequences at the four DNA barcode regions among related species demonstrates that DNA barcoding is especially useful in identifying TIPS that are morphologically similar to other species.
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Gracilaria parva sp. nov. (Gracilariales, Rhodophyta) a Diminutive Species from the Tropical Eastern Pacific
DNA sequencing of the plastid encoded rbcL gene supported by morpho-anatomical features reveals Gracilaria parva sp. nov. from Panama and Ecuador in the tropical eastern Pacific Ocean. In the rbcL phylogram, G. parva occurs in a clade sister to the western Atlantic species G. galatensis. Morphologically and anatomically, G. parva is distinguished from two similar, described tropical eastern Pacific species, G. brevis and G. veleroae by its small size, to 2.5 cm tall with branch widths mostly <2 mm occasionally to 4 mm, and by its two to three cell layered cortex. Gracilaria brevis and G. veleroae are taller, have wider branches, and a one cell layered cortex. DNA sequencing is needed to resolve the many diminutive species in the tropical eastern Pacific, particularly those occurring in turf communities. DNA sequencing of historical type specimens from the 19th and 20th centuries is also needed to correctly apply names in this region.
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- Award ID(s):
- 1737071
- PAR ID:
- 10379975
- Date Published:
- Journal Name:
- Taxonomy
- Volume:
- 2
- Issue:
- 1
- ISSN:
- 2673-6500
- Page Range / eLocation ID:
- 48 to 56
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/taxonomy2010004
