Wheat-rye T1BL.1RS translocation is widespread worldwide as the genes on 1RS arm have positive effect on stress resistance, grain yield and adaptation ability of wheat. Nowadays, the T1BL.1RS wheat cultivars have become susceptible to rust diseases because of the monophyletic ('Petkus') origin of 1RS. Here we report and discuss the production and detailed investigation of a new T1BL.1RS translocation line carrying 1RS with widened genetic base originating from Secale cereanum. Line '179' exhibited improved spike morphology traits, resistance against stripe rust and leaf rust, as well as higher tillering capacity, fertility and dietary fiber (arabynoxylan) content than the parental wheat genotype. Comparative analyses based on molecular cytogenetic methods and molecular (SSR and DArTseq) makers indicate that the 1RS arm of line '179' is a recombinant of S. cereale and S. strictum homologues, and approximately 16% of its loci were different from that of 'Petkus' origin. 162 (69.5%) 1RS-specific markers were associated with genes, including 10 markers with putative disease resistance functions and LRR domains found on the subtelomeric or pericentromeric regions of 1RS. Line '179' will facilitate the map-based cloning of the resistance genes, and it can contribute to healthy eating and a more cost-efficient wheat production.
Barley chromosome 5H, carrying important QTLs for plant adaptation and tolerance to abiotic stresses, is extremely instable in the wheat genetic background and is eliminated in the early generations of wheat-barley crosses. A spontaneous wheat-barley 5HS-7DS.7DL translocation was previously obtained among the progenies of the Mv9kr1 x Igri hybrid. The present work reports on the transfer of the 5HS-7DS.7DL translocation into a modern wheat cultivar, Mv Bodri, in order to use it in the wheat breeding program. The comparison of the hybridization bands of DNA repeats HvT01, pTa71, (GAA)n and the barley centromere-specific (AGGGAG)n in Igri barley and the 5HS-7DS.7DL translocation, together with the visualization of the barley chromatin made it possible to determine the size of the introgressed barley segment, which was approximately 74% of the whole 5HS. Of the 29 newly developed PCR markers, whose source ESTs were selected from the Genome Zipper of barley chromosome 5H, 23 were mapped in the introgressed 1-0.26 FL 5HS bin, three were located in the missing C-0.26 FL region, while three markers were specific for 5HL. The translocation breakpoint was flanked by markers Hv7502 and Hv3949. A comparison of the parental wheat cultivars and the wheat-barley introgression lines indicated that the presence of the translocation improved tillering ability in the Mv9kr1 and Mv Bodri genetic background. The similar or better yield components under high- or low-input cultivation environments, respectively, indicated that the 5HS-7DS.7DL translocation had little or no negative effect on yield components, making it a promising genotype to improve wheat genetic diversity. These results promise to accelerate functional genomic studies on barley chromosome 5H and to support pre-breeding and breeding research on wheat.
- MeSH
- chromatin genetika metabolismus MeSH
- chromozomy rostlin MeSH
- exprimované sekvenční adresy MeSH
- genetická vazba MeSH
- genetické markery MeSH
- genotyp MeSH
- hybridizace genetická MeSH
- ječmen (rod) genetika MeSH
- mapování chromozomů MeSH
- pšenice genetika MeSH
- translokace genetická * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Goat grasses (Aegilops spp.) contributed to the evolution of bread wheat and are important sources of genes and alleles for modern wheat improvement. However, their use in alien introgression breeding is hindered by poor knowledge of their genome structure and a lack of molecular tools. The analysis of large and complex genomes may be simplified by dissecting them into single chromosomes via flow cytometric sorting. In some species this is not possible due to similarities in relative DNA content among chromosomes within a karyotype. This work describes the distribution of GAA and ACG microsatellite repeats on chromosomes of the U, M, S and C genomes of Aegilops, and the use of microsatellite probes to label the chromosomes in suspension by fluorescence in situ hybridization (FISHIS). Bivariate flow cytometric analysis of chromosome DAPI fluorescence and fluorescence of FITC-labelled microsatellites made it possible to discriminate all chromosomes and sort them with negligible contamination by other chromosomes. DNA of purified chromosomes was used as a template for polymerase chain reation (PCR) using Conserved Orthologous Set (COS) markers with known positions on wheat A, B and D genomes. Wheat-Aegilops macrosyntenic comparisons using COS markers revealed significant rearrangements in the U and C genomes, while the M and S genomes exhibited structure similar to wheat. Purified chromosome fractions provided an attractive resource to investigate the structure and evolution of the Aegilops genomes, and the COS markers assigned to Aegilops chromosomes will facilitate alien gene introgression into wheat.
- MeSH
- chromozomy rostlin genetika MeSH
- hybridizace in situ MeSH
- průtoková cytometrie MeSH
- pšenice genetika MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND AIMS: Aegilops markgrafii (CC) and its natural hybrids Ae. triuncialis (U(t)U(t)C(t)C(t)) and Ae. cylindrica (D(c)D(c)C(c)C(c)) represent a rich reservoir of useful genes for improvement of bread wheat (Triticum aestivum), but the limited information available on their genome structure and the shortage of molecular (cyto-) genetic tools hamper the utilization of the extant genetic diversity. This study provides the complete karyotypes in the three species obtained after fluorescent in situ hybridization (FISH) with repetitive DNA probes, and evaluates the potential of flow cytometric chromosome sorting. METHODS: The flow karyotypes obtained after the analysis of 4',6-diamidino-2-phenylindole (DAPI)-stained chromosomes were characterized and the chromosome content of the peaks on the flow karyotypes was determined by FISH. Twenty-nine conserved orthologous set (COS) markers covering all seven wheat homoeologous chromosome groups were used for PCR with DNA amplified from flow-sorted chromosomes and genomic DNA. KEY RESULTS: FISH with repetitive DNA probes revealed that chromosomes 4C, 5C, 7C(t), T6U(t)S.6U(t)L-5C(t)L, 1C(c) and 5D(c) could be sorted with purities ranging from 66 to 91 %, while the remaining chromosomes could be sorted in groups of 2-5. This identified a partial wheat-C-genome homology for group 4 and 5 chromosomes. In addition, 1C chromosomes were homologous with group 1 of wheat; a small segment from group 2 indicated 1C-2C rearrangement. An extensively rearranged structure of chromosome 7C relative to wheat was also detected. CONCLUSIONS: The possibility of purifying Aegilops chromosomes provides an attractive opportunity to investigate the structure and evolution of the Aegilops C genome and to develop molecular tools to facilitate the identification of alien chromatin and support alien introgression breeding in bread wheat.
- MeSH
- chromozomy rostlin genetika MeSH
- genom rostlinný * MeSH
- hybridizace in situ fluorescenční MeSH
- indoly MeSH
- karyotyp MeSH
- karyotypizace MeSH
- konzervovaná sekvence genetika MeSH
- lipnicovité genetika MeSH
- metafáze MeSH
- průtoková cytometrie metody MeSH
- pšenice genetika MeSH
- sekvenční homologie nukleových kyselin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
