Production and Molecular Cytogenetic Identification of Wheat-Alien Hybrids and Introgression Lines

Abstract

Barley, rye, Aegilops and Thinopyrum (syn. Agropyron) species belonging to the Triticeae tribe have large genetic diversity and serve as a valuable genetic reservoir for wheat improvement. Many of these species have been used for more than a century for the production of wheat × alien hybrids and introgression lines. The most up-to-date molecular cytogenetic techniques make it possible to detect and identify alien chromosomes in the wheat genome. The first methods used to identify rye, barley, Aegilops and Thinopyrum chromosomes in the wheat genome were C- and N-banding. Genomic in situ hybridization (GISH) is the most accurate way of detecting the translocation breakpoint in introgression lines. Alien chromosomes can be identified in the wheat genome using fluorescence in situ hybridization (FISH) with the help of repetitive DNA probes.Multicolor GISH (mcGISH) was developed to demonstrate the various genomes in polyploid plant species and in interspecific and intergeneric hybrids, amphiploids and derivatives. Sequential GISH and FISH are useful methods for identifying alien translocations in the wheat genome.