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Cytological and molecular characterization of wheat-Hordeum chilense chromosome 7Hch introgression lines

Mattera, M. G., Ávila, C. M., Atienza, S. G., Cabrera, A.
Euphytica 2015 v.203 no.1 pp. 165-176
wheat, chromosome translocation, genetic markers, substitution lines, microsatellite repeats, barley, Hordeum vulgare, DNA probes, Triticum aestivum, carotenoids, genotyping, introgression, genetic recombination, in situ hybridization, seeds, chromosomes, plant breeding, Hordeum chilense, expressed sequence tags, biochemical pathways, homozygosity, phytoene synthase
Chromosome 7Hᶜʰof Hordeum chilense carries the Phytoene synthase 1 (Psy1) gene encoding the first step in the carotenoid biosynthetic pathway. As such it can be used in the improvement of seed carotenoid content in wheat. Four introgressions of chromosome 7Hᶜʰinto wheat have been characterized by in situ hybridization of labeled DNA probes and by several sets of DNA markers. Chromosome-specific SSR were used for the identification of wheat chromosomes. Besides 113 conserved orthologous set (COS) markers were tested for homoeologous group 7, of which 97 amplified in H. chilense and 32 were polymorphic between H. chilense and wheat, and 28 expressed sequence tag (EST) barley markers previously allocated to chromosome 7. A total of 60 markers (32 COS and 28 EST) were allocated to chromosome 7Hᶜʰwith 28 assigned to 7HᶜʰS and 22 to 7HᶜʰL. A combination of in situ probing and marker genotyping have shown that among the four introgressions there was a substitution line 7Hᶜʰ(7D), a ditelosomic addition line for the long arm of 7Hᶜʰand two homozygous centric translocations 7HᶜʰS·2DS and 7HᶜʰS·5AL. The Psy1 gene was localized on the short arm of 7Hᶜʰ. The positions of markers from the international barley consortium map (IBSC2012) were determined and the comparative arm location between H. chilense and H. vulgare is discussed. The genetic stocks characterized here include new wheat-H. chilense recombinations useful for genetic studies and with a potential for breeding.