Methods for establishing distinctness of cereal-grain genotype in cultivarregistration

There are many tests of genotypic identity with the potential to establish the distinctness of a cultivar that is offered for registration. These incl ude the range of laboratory-based tests for protein composition and for DNA testing, in addition to judging the more conventional morphological descri ptors. whilst the availability of so many methods is a great advantage, if becomes more difficult to select the most suitable sub-set of methods to es tablish distinctness for a specific case. As a likely solution to this prob lem, a computer-based program (WhatWheat) has been adapted from its origina l identification role to assist in the task of establishing distinctness. N ormally, the program provides a large two-way table summarising the results for a set of established cultivars on the basis of a range of testing meth ods. This can be interrogated in various ways to expedite identification of a sample. If WhatWheat were lo be used for cultivar-group classification, an initial test should be performed, and the result entered for the cultiva r being offered for registration. More likely, the information provided wit h the nomination of the new cultivar would serve this function (e.g. its mo rphological description). Further selection of tests would then occur, base d on the result of the first test information in providing a sub-set of cul tivars, and the potential differentiating ability of those next tests. The additional inclusion of pedigree information would further serve to narrow the range of relevant cultivars for examination.