Characterization of Inter-varietal Chromosome Substitution Lines of Wheat Using Molecular Markers

Several sets of wheat inter-varietal chromosome substitution lines (SLs) have been produced over the last fifty years at the CRI (formerly RICP) in Prague-Ruzyně, based on cytogenetic manipulations using aneu - ploids. Lines with defined genes have been obtained which significantly influence growth habit and flowering time and these have been used particularly in the study of the genetics and physiology of flowering. The sets of lines include substitutions of homoeologous group 5 chromosomes carrying vrn genes that control vernalisa- tion response, homoeologous group 2 chromosomes with Ppd genes controlling photoperiodic sensitivity, and some other substitutions, particularly those with chromosome 3B of the Czech alternative variety Ceska Přesivka where a novel flowering time effect was located. Although the phenotypic and cytological analysis of substitution lines has been continually carried out during backcrossing generations, only the use of molecular markers can allow an unambiguous characterization to verify that substitutions are correct and complete. This analysis has allowed incorrect substitutions or partial substitutions to be identified and discarded. This paper summarizes the results of recent molecular checks of the substitution line collections at CRI.