GO (Gene Ontology) for describing
genes and their products.
TO (Trait Ontology) for description of phenotypic traits related to mutants and QTLs.
PO (Plant Ontology) for describing plant specific morphology, anatomy and development related terms.
The codes are listed along with examples (not exhaustive lists) of the kinds of experiments that would fall into each category. For every evidence category, there is a flexibility for the curators to exercise judgement about the quality of the evidence, and how well it supports annotation to a node within each ontology. The distinction between "TAS" and "NAS" is particularly sensitive to interpretation. We will appreciate your feedback, if you think that we should include other types of methodologies under the sub-categories and expand the framework of evaluation. Please feel free to communicate your thoughts at email@example.com.