Wheat pre-breeding using wild progenitors

Abstract

To facilitate the use of wheat wild relatives in conventional breedingprograms, a wheat pre-breeding activity started at ICARDA in 1994/1995season. Preliminary results of gene introgression from wild diploidprogenitors, Triticum urartu, T. baeoticum, Aegilops speltoides andAe. tauschii and tetraploid T. dicoccoides are described. Crosseswith wild diploid Triticum spp. yielded high variation in plant andspike morphology. Synthetic hexaploids were produced from crosses of alocal durum wheat landrace `Haurani' with two Ae. tauschii accessions. Both Ae. tauschii accessions carry hybrid necrosis allelesthat gave necrotic plant phenotypes in crosses with some bread wheats.Backcross progenies with agronomical desirable traits, i.e. high spikeproductivity, short plant stature, earliness, drought tolerance and highproductive tillering, were identified in crosses of durum wheat with wild Triticum spp. and in a cross of one of the hexaploid synthetics with alocally adapted bread wheat cv. `Cham 6'. Resistance to yellow rust wasfound in durum wheat crosses with the three wild Triticum spp. andAe. speltoides and leaf rust resistance was identified in crosses withT. baeoticum and Ae. speltoides. The results show that wheatimmediate progenitors may be a valuable and readily accessible source ofnew genetic diversity for wheat improvement.