Amphidiploids serve as a bridge for transferring genes from wild species into wheat. In this study, five amphidiploids with AABBUU and AABBNN genomes were produced by spontaneous chromosome doubling of unreduced triploid F1 gametes from crosses between diploid Aegilops (A. umbellulata accessions CIae 29 and PI 226500, and A. uniaristata accession PI 554419) and tetraploid Triticum turgidum (ssp. durum cultivar Langdon and ssp. dicoccum accessions PI 94 668 and PI 349045) species. The composition of high-molecular-weight glutenin subunits (HMW-GS) in these amphidiploids and in their parental A. umbellulata and A. uniaristata species was analysed. As expected, the amphidiploids from T. turgidum ssp. dicoccum accession PI 944668 or PI 349045 and A. umbellulata accession CIae 29 or PI 226500 and A. uniaristata accession PI 554419 showed the same HMW-GS patterns as those of their Aegilops parents, because HMW-GS genes were all silenced in the T. turgidum ssp. dicoccum parents. The amphidiploids from CIae 29 and Langdon inherited all of the HMW-GS genes from their parents except for the Uy type. Using 10 and 15% sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and 10% urea/SDS–PAGE, 11 Ux and ten Uy types in 16 combinations were observed in 48 A. umbellulata accessions, and two Nx and two Ny types in two combinations were detected in six A. uniaristata accessions. These novel HMW-GS variants may provide new genetic resources for improving the quality of wheat.

High levels of soil aluminium place serious constraints on wheat production on acidic soils, especially in the tropical areas of Africa and South America. Conventional plant breeding has improved the tolerance of the wheat crop, but available genetic variation is limited. The wild relatives of wheat provide a valuable gene pool for the introduction of further genetic variation. One wild species, Aegilops uniaristata Vis. (2n=2x=14,NN), is being utilized as a new source of tolerance. Of the addition lines of individual N genome chromosomes of A. uniaristata to wheat (Triticum aestivum L.) which have been established and characterized, chromosome 3N has been shown to confer tolerance to wheat. The three substitution lines in which 3N replaces the homoeologous wheat chromosomes, 3A, 3B or 3D, have also been produced. Growing plants to maturity in a low pH/high Al hydroponics system confirmed that chromosome 3N conferred tolerance to the substitution lines as well as to the addition line. By manipulating the genetic control of homoeologous chromosome pairing, chromosome 3N is being recombined with its wheat homoeologues in order to introduce a smaller alien segment which carries the gene(s) for tolerance but not the agronomically unacceptable brittle rachis gene also carried on chromosome 3N.