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Wheat Information Service
Number 81:50-55 (1995)

IV. Proposal

Suggested guidelines for the nomenclature and abbreviation of the genetic stocks of wheat, Triticum aestivum L. em Thell., and its relatives1

W. J. Raupp, B. Friebe, and B. S. Gill

Department of Plant Pathology, Throckmorton Hall, Kansas State University, Manhattan, KS 66506-5502, USA.

The current nomenclature for describing the aneuploids of common wheat was introduced by Sears in 1954 and described in detail by Kimber and Sears in 1968. This nomenclature can be lengthy, and its use in manuscripts and descriptive figures cumbersome. Additionally, the needs of computerized databases require a shortening of these terms to save time and storage space. The ability to search lists of stocks suggests the need for succinct, descriptive abbreviations for the genetic stocks in wheat. GrainGenes, the wheat genome database, is no exception as search criteria can yield several screens of data. The purpose of this communication is to provide a list of recommended abbreviations for the aneuploid lines and genetic stocks in wheat.

Several recommended guidelines presented by Kimber and Sears (1968) will be used. These include designating:

i) telocentric chromosomes with the letter "t",
ii) isochromosomes with the letter "i",
iii) the ability of chromosomes to pair with superscripts following the chromosome symbols. The actual pairing may vary considerably from cell to cell. The idealized pairing configuration is indicated in all cases even though it may rarely form,
iv) chromosome status shown by the chromosome number followed by symbols indicating the configuration,
v) chromosome arms by S (genetically short) or L (genetically long), and
vi) substituted chromosomes by the homoeologous group number and genome designation. The designation of the chromosome that was replaced follows in parentheses.

Publications by Gill (1986) and Gill et al. (1991) added additional descriptors for wheat genetic stocks. The symbols were based on suggestions by the Chicago (1966) and Paris Conferences (1971) for Standardization in Human Cytogenetics. Where applicable, these conventions will also be used:

vii) single and three letter designations specify rearranged chromosomes, such as "del" for deletion and "r'' for ring chromosome,
viii) the short system for defining translocation lines includes only the break points and the following punctuation: " . " indicates a break at the centromere, a dash "-", indicates an interstitial breakpoint, and a slash " / " indicates an unknown breakpoint,
ix) the detailed system describes translocation lines by defining their band composition and the additional symbols, ": " break (terminal deletion), ":: " break and join, and
x) a translocation chromosome is indicated by a "T"preceeding a description of the translocation.
Further descriptions of translocated chromosomes are given in Gill et al. (1991) and will be described as needed.
1 This is contribution 95-541-J from the Kansas Agricultural Experiment Station, Manhattan.

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