Use of multiparental inbred populations to determine allelic relationshipsof molecular markers

The assessment of polymorphism exhibited by molecular markers is an arduous but essential task that facilitates the use of molecular tools by breeders and :geneticists. For that purpose, the value of a wheat composite populat ion was assessed for characterizing the diversity of restriction fragment l ength polymorphism (RFLP) markers developed by INRA-Genoble. The polymorphi sm of 13 genomic probes was measured over a set of 80 inbred lines randomly extracted by single-seed descent from a composite-cross of 16 wheat lines. The 13 probe enzyme combinations revealed 27 loci with codominant polymorp hism. As many bands were so far unmapped, the segregational analysis of the progenies appeared very suitable for complex patterns, both in determining allelic relationships and in revealing linkage between loci. Allelic diver sity, band sizes and chromosomal location assessed from nullisomic-tetrasom ic lines are given for the 27 loci.