Production of synthetic wheat lines to exploit the genetic diversity of emmer wheat and D genome containing Aegilops species in wheat breeding

Abstract Due to the accumulation of various useful traits over evolutionary time, emmer wheat (Triticum turgidumsubsp.dicoccumanddicoccoides, 2n = 4x = 28; AABB), durum wheat (T. turgidumsubsp.durum, 2n = 4x = 28; AABB),T. timopheevii(2n = 4x = 28; AAGG) and D genome containingAegilopsspecies offer excellent sources of novel variation for the improvement of bread wheat (T. aestivumL., AABBDD). Here, we made 192 different cross combinations between diverse genotypes of wheat andAegilopsspecies including emmer wheat × Ae. tauschii(2n = DD or DDDD), durum wheat × Ae. tauschii,T. timopheevii × Ae. tauschii,Ae. crassa × durum wheat,Ae. cylindrica × durum wheat andAe. ventricosa × durum wheat in the field over three successive years. We successfully recovered 56 different synthetic hexaploid and octaploid F2lines with AABBDD, AABBDDDD, AAGGDD, D1D1XcrXcrAABB, DcDcCcCcAABB and DvDvNvNvAABB genomes via in vitro rescue of F1embryos and spontaneous production of F2seeds on the Flplants. Cytogenetic analysis of F2lines showed that the produced synthetic wheat lines were generally promising stable amphiploids. Contribution of D genome bearingAegilopsand the less-investigated emmer wheat genotypes as parents in the crosses resulted in synthetic amphiploids which are a valuable resource for bread wheat breeding.