Reproductive and genetic roles of the maternal progenitor in the origin of common wheat ( L.).

Common wheat ( L., AABBDD genome) is thought to have emerged through natural hybridization between L. (AABB genome) and Coss. (DD genome). Hybridization barriers and doubling of the trihaploid F hybrids' genome (ABD) via unreduced gamete fusion had key roles in the process. However, how , the maternal progenitor, was involved in these mechanisms remains unknown. An artificial cross-experiment using 46 cultivated and 31 wild accessions and a single tester with a very short genetic distance to the common wheat D genome was conducted. Cytological and quantitative trait locus analyses of F hybrid genome doubling were performed. The crossability and ability to cause hybrid inviability did not greatly differ between the cultivars and wild accessions. The ability to cause hybrid genome doubling was higher in the cultivars. Three novel loci for hybrid genome doubling, which influenced unreduced gamete production in F hybrids, were identified. Cultivated might have increased the probability of the emergence of common wheat through its enhanced ability to cause genome doubling in F hybrids with . The ability enhancement might have involved alterations at a relatively small number of loci.