Molecular aids for integration of alien chromatin through wide crosses

Wide crosses in wheat have now been performed for over 100 years. In that t ime, approximately 100 genes have been transferred for numerous traits, inc luding biotic and abiotic stresses and value-added traits. Resistance genes from alien sources do become defeated with rime, so the search for additio nal variability must continue. Recent screening of alien species has identi fied accessions with multiple pest resistance plus combinations of pest res istance and value-added traits. The majority of existing induced recombinan ts are of a noncompensating type with considerable linkage drag, so sequent ial useage of Ph mutants is recommended to produce smaller interstitial rec ombinants. Molecular methods including GISH, RAPD, RFLP, AFLP, and microsat ellites, are being widely used to identify integrated alien chromosomes, ch romosome segments, and genes.