New sources of rust resistance from alien species: meliorating linked defects and discovery

This paper presents a review of projects undertaken over the past 2 decades aimed at improving the yield and/ or quality attributes of translocation lines carrying rust resistance genes from species related to wheat, so as to make these lines more suitable for use in breeding programs. Homeologous recombination between the alien chromosome segments and normal wheat chromosomes was induced in a ph1bph1b background. Lines with shortened alien chromatin were selected using dissociation patterns of molecular-based markers. A new line of bread wheat was developed containing a shortened chromosome 1RS segment carrying rust resistance gene SrR (Secale cereale L.), in which a defect affecting dough- quality appears to have been deleted. In addition, several advanced lines were produced with modified 6Ae#1L chromosome segments with Sr26 (Thinopyrum ponticum), 2S#1 chromosome segments with Sr32, and a previously unnamed gene, a 2S#2 chromosome segment with Sr39 (Triticum speltoides), 4G#1 chromosome segments with Sr37, and 2G#2 chromosome segments with Sr40 (T. timopheevii).