Approaches in Nematode
Taxonomy
Excerpted from a lecture by Philippe Castagnone-Serena
INRA/University of Nice, France (ONTA meeting, La Serena, Chile, 2013)
Accurate species-level identification is essential for
implementation of management strategies of plant-parasitic species.
Several approaches are available, each with advantages and constraints:
Morphometrics
The traditional approach
Constraints:
o
There is not huge diversity among nematodes
o
There is intraspecific variation in virulence and
biology
o
The approach is time consuming requiring multiple
measurements of multiple individuals
o
Requires specific skills and training
Biochemical
Including antibodies, ELISA tests and isoenzymes
Constraints
o
Known patterns are limited to a few genera
o
Depends on high quality of proteins
DNA-based Technologies
Techniques that probably originated with Curran et al (1988) with use of
RFLPs and have expanded with developments in technology.
Evolving Methods:
o
Real-time PCR – portable equipment available,
90-minute process.
o
LAMP – loop-mediated isothermal amplification,
requires <1 hour.
o
Barcoding – based on mithochondrial DNA or
Ribosomal DNA
o
Barcode of Life project currently has 1600
barcodes available.
Integrated Taxonomy
Requirements for future development of Nematode Systematics.
o
Need morphological, morphometric and biological
taxonomy to delineate ‘species”
boundaries, at whatever level of difference is considered sufficient or
useful as a category designation.
o
The need to establish and assign a taxonomic
binomial to a molecular signature.