Molecular analysis of leaf-rust resistant introgression lines obtained by crossing hexaploid wheat Triticum aestivum with tetraploid wheat Triticum timopheevii

Abstract

Twenty-four Triticum eastivum x T. timopheevii hybrid lines developed on the basis of five varieties of common wheat and resistant to leaf rust were analyzed by the use of microsatellite markers specific for hexaploid common wheat T. aestivum. Investigation of intervarietal polymorphism of the markers showed that the number of alleles per locus ranged from 1 to 4, depending on the marker (2.5 on average). In T. timopheevii, amplification fragments are produced by 80, 55, and 30% of primers specific to the A, B, and D common wheat genomes, respectively. Microsatellite analysis revealed two major areas of introgression of the T. timopheevii genome: chromosomes of homoeological groups 2 and 5. Translocations were detected in the 2A and 2B chromosomes simultaneously in 11 lines of 24. The length of the translocated fragment in the 2B chromosome was virtually identical in all hybrid lines and did not depend on the parental wheat variety. In 15 lines developed on the basis of the Saratovskaya 29, Irtyshanka, and Tselinnaya 20, changes occurred in the telomeric region of the long arm of the 5A chromosome. Analysis with markers specific to the D genome suggested that introgressions of the T. timopheevii genome occurred in chromosomes of the D genome. However, the location of these markers on T. timopheevii chromosomes is unknown. Our data suggest that the genes for leaf-rust resistance transferred from T. timopheevii to T. aestivum are located chromosomes of homoeological group 2.