Molecular diversity of common wheat introgression lines (T. aestivum/T. timopheevii)

We investigated genetic diversity of T. aestivum/T. timopheevii introgression lines in relation to microsatellite loci and resistance to fungal diseases. The genotyping of hybrid lines and parental cultivars of common wheat with 143 Simple Sequence Repeat (SSR) markers revealed, respectively, 521 and 440 alleles or 3.24/2.73 alleles on average per microsatellite locus. A comparison of individual chromosomes with respect to the indices of genetic diversity revealed that chromosomes 4D and 5D show the lowest diversity for SSR loci, both in parents and hybrid lines, while chromosomes 5B and 6A presented the highest indices (0.62–0.68). Evaluation of SSR polymorphisms and indices in three genomes of introgression wheat lines revealed that chromosomes of genome B presented higher indices than genomes A and D (B > A > D), which may be the result of alien introgression in these chromosomes. A comparison of the results of the molecular and phytopathological tests indicates that despite the stringent selection for resistance to leaf rust during early generations, and a large number of subsequent selfing generations, the genetic diversity of introgression lines, with respect to microsatellite loci, is preserved, which is indicative of the stability of the alien genetic material transmitted to the common wheat genome.