Plant DNA C-values Database

How to search the Plant DNA C-values Database

The Plant C-values database has been organized so that you can search either the whole database, or a subset of it (e.g. angiosperms).

To use the database follow the five simple steps below.

  1. Select which database you want to search by choosing one of the following:
  2. Enter your email address in the box on the query form.
  3. Select output fields on the query form.
  4. Genus and species will automatically be displayed with 1C-value data given in picograms (pg).
    To display 1C, 2C or 4C values in megabases (Mb) or pg then select the appropriate option in the 'C-values' field.
    If you want additional information e.g. family, chromosome number (if known), ploidy level (if known) etc. then click in the appropriate boxes.

    In addition, users of the Angiosperm DNA C-values database have the following two options:

    1. Users can chose to display either the traditional or APG (Angiosperm Phylogeny Group) family name
    2. Users can chose to display the angiosperm group to which the species belongs (i.e. basal angiosperm, monocot, eudicot)
  5. Refine your search by selecting conditions on the query form.

    For example you can ask the database to give you C-values for just diploid Liliaceae by entering 'Liliaceae' in the family box and entering '2' in the ploidy box.

    The search facilities enable wild card searches if you are uncertain of an exact spelling. For help with setting search criteria see below.

  6. Run query.

    Press 'Run Query' button.

Help with searching the C-values database

  1. Wild card searches
  2. From/to searches
  3. Sorting results
  4. Help with family nomenclature in the angiosperms
  5. Abbreviation used in the Query results
  1. Wild card searches

    The asterix * can be used for searches where users are uncertain about part of a name.

    Example: Entering genus = Li* or genus = *ipa would return any genus beginning with 'Li' or ending with 'ipa'.

    Of course, these two approaches above can be combined.

  2. From/to searches

    To restrict searches based on numeric data (i.e. chromosome number, ploidy level, DNA amount) use the 'from' and 'to' boxes.

    Example 1: To limit the results of a query to taxa with diploid chromosome numbers between 18 and 36 (inclusive) enter 18 in the 'from' box and 36 in the 'to' box for chromosome numbers.

    Example 2: To limit the search to taxa with only 18 chromosomes then place this number in both the 'from' and 'to' boxes.

    Example 3: To select all records having a diploid number of 18 or greater enter 18 in the 'from' box and leave the 'to' box empty.

  3. Sorting results

    The results of searches are automatically sorted by increasing 1C DNA amounts in picograms.

    To sort the results by family, genus, species, taxonomic authority, chromosome number or ploidy level then select appropriate choice from the drop-down box under the option 'Sort by' at the bottom of the Query form.

  4. Help with family nomenclature in angiosperms

    Users interested in searching genera and species in a particular angiosperm family should note the following nomenclature practice that has been adopted in this database:

    According to the International Code of Botanical Nomenclature (International Association for Plant Taxonomy, Utrecht, 1992) the names of plant families must end in -aceae. However, eight plant families are exceptions in that each has two alternative names, both of which are correct under the Botanical Code. One is a standard name, ending in -aceae, the other is an exception, sanctioned by long usage. these and their alternatives are the following:

    Standard/APG family name Non-standard/Traditional family name
    Arecaceae Palmae
    Poaceae Gramineae
    Brassicaceae Cruciferae
    Fabaceae Leguminosae
    Clusiaceae Guttiferae
    Apiaceae Umbelliferae
    Lamiaceae Labiatae
    Asteraceae Compositae

    To be consistent with the published DNA lists (e.g. Bennett and Smith, 1976, 1991; Bennett et al., 1982 and 2000; Bennett and Leitch, 1995, 1997, 2005 and 2011) the non-standard plant names are retained in this database and are used when searches select the Traditional family name. If the user chooses to search using the APG family name then the family name ending in -aceae will be used.

  5. Abbreviation used in the results

    The following abbreviations are used:

    Estimation method
    Feulgen microdensitometry
    flow cytometry using one of the following fluorochromes:
    propidium iodide
    ethidium bromide
    ethidium bromide and olivomycin
    microdenistometry using DAPI
    Reassociation kinetics
    Chemical extraction
    Angiosperm group
    basal angiosperm
    Life cycle type
    Flagella number