Independent wheat B and G genome origins in outcrossing Aegilops progenitor haplotypes.

Abstract

The origin of modern wheats involved alloploidization among related genomes. To determine if Aegilops speltoides was the donor of the B and G genomes in AABB and AAGG tetraploids, we used a 3-tiered approach. Using 70 amplified fragment length polymorphism (AFLP) loci, we sampled molecular diversity among 480 wheat lines from their natural habitats encompassing all S genome Aegilops, the putative progenitors of wheat B and G genomes. Fifty-nine Aegilops representatives for S genome diversity were compared at 375 AFLP loci with diploid, tetraploid, and 11 nulli-tetrasomic Triticum aestivum wheat lines. B genome-specific markers allowed pinning the origin of the B genome to S chromosomes of A. speltoides, while excluding other lineages. The outbreeding nature of A. speltoides influences its molecular diversity and bears upon inferences of B and G genome origins. Haplotypes at nuclear and chloroplast loci ACC1, G6PDH, GPT, PGK1, Q, VRN1, and ndhF for approximately 70 Aegilops and Triticum lines (0.73 Mb sequenced) reveal both B and G genomes of polyploid wheats as unique samples of A. speltoides haplotype diversity. These have been sequestered by the AABB Triticum dicoccoides and AAGG Triticum araraticum lineages during their independent origins.

• Authors: B Kilian, H Ozkan, O Deusch, S Effgen, A Brandolini, J Kohl, W Martin, F Salamini
• Journal: Molecular biology and evolution (Mol Biol Evol) Vol. 24 Issue 1 Pg. 217-27 (Jan 2007) ISSN: 0737-4038 [Print] United States
• PMID: 17053048 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Crosses, Genetic
• Genome, Plant
• Haplotypes
• Hybridization, Genetic
• Phylogeny
• Poaceae (genetics)
• Polymorphism, Restriction Fragment Length
• Polyploidy
• Triticum (genetics)