Taxonomy of Plant Pathogenic Nematodes - Use of SSU and LSU rDNA Sequences for Phylogenetic Reconstruction and DNA barcoding

Taxonomy is the process of the classification, the application
of names (nomenclature), and the practice of identification. Classification
is an iterative process that follows the scientific method.
Knowledge of relationships from previous findings is refined using
the most powerful methods available. The validity of the results
and conclusions are scrutinized through the peer review
process. The scientific community begins to use the new classification
system if, in their scientific opinion, it is an improvement
over previous classifications. Over the past 20 years DNA:DNA
hybridization and sequence analyses of individual genes informed
classifications. Now new inexpensive technology allows researchers
to compare sequences of multiple genes and even of entire
genomes to study the genetic diversity of bacterial populations
and classify organisms. If these studies include appropriate
type strains, the information generated may be developed into
proposals that could result in changes in nomenclature. The application
of names to circumscribed taxa is conducted according
to rules and standards presented by internationally recognized
codes of nomenclature. The International Code of Nomenclature
of Prokaryotes regulates the nomenclature for species, subspecies
and higher taxa. The International Standards for Naming Pathovars
of Plant Pathogenic Bacteria, regulates the nomenclature of
pathovars and provides recommendations for changes in nomenclature
that involve the proposal of pathovars as species or subspecies.
Results from current genomic studies may lead to the
identification of genetic signatures for Pseudomonas syringae
pathovars that could be used as