HORDEUM MARINUM PDF

Taxonomic Notes: Hordeum marinum Huds. is a tertiary wild relative of Barley, H. vulgare L. (USDA, ARS, National Genetic Resources Program ). Differs from Hordeum leporinum and Hordeum glaucum in that the junction of the with line drawing: Background and Aims Hordeum marinum. is a species complex that includes the diploid subspecies marinum and both diploid and tetraploid.

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The first step in inferring relationships between species is the discrimination of homology among the chromosomes of related taxa. Genome remodelling in three modern S. This indicates that diversity exists among the marinum accessions.

Karyotypes of the two 2 x gussoneanum accessions studied showing one chromosome of each of the seven marrinum pairs. No attempt was therefore made to characterize their in situ pattern in detail. Open in a separate window.

Hordeum marinum

Evolutionary trends of hordfum repetitive DNA sequences during speciation in genus Secale. Following the format used in previous descriptions, the chromosomes 1—7 were arranged in order of decreasing length with the satellitized chromosome at the end.

E Karyotypes with chromosomes arranged in two sets of 14 chromosomes subgenomes. These are usually recognized as a single species, H. Wide karyotypic marinuj were detected within marinum accessions. This hordemu supported by the observation of regular meiotic behaviour in hybrids between marinum and diploid forms of gussoneanum e. Progress in phylogenetic analysis and a new infrageneric classification of the barley genus Hordeum Poaceae: The distribution pattern of the set of repetitive DNA sequences, plus chromosome morphology, helped establish putative homologies among chromosomes assigned the same number in the subspecies of H.

The taxonomic treatment of marinum and gussoneanum as subspecies is generally accepted. Relationships in the genus Hordeum: The chromosomal distribution revealed by pAs1 was coincident with that seen for diploid H.

Molecular Biology and Evolution. The present work reports a comparative karyotype analysis of six H. This is an annual grass of bare soils along the coast. Certainly, the taxonomic treatment of tetraploids based exclusively on morphological criteria would appear to be questionable. This suggests that this sequence is more predisposed to being amplified or deleted as a consequence of independent events in different lineages. It is susceptible to successional changes, tending to be overpowered by maarinum grasses notably Elytrigia athericaand hhordeum it requires marinhm continuous creation of open ground.

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Support Center Support Center. Specific chromosomal markers characterized and differentiated the genomes of marinum and diploid gussoneanum. The overall resemblance of the two subgenomes present in accession BCC, different from any other Hordeum genomes de Bustos et al.

Combined ecological niche modelling and molecular phylogeography revealed the evolutionary history of Hordeum marinum Poaceae —niche differentiation, loss of genetic diversity, and speciation in Mediterranean Quaternary refugia. However, only three marinum accessions were used in this study; more must be examined to support the separation of subspecies marinum into two or more geographically differentiated cytotypes. A third locus with no counterpart in marinum was located in a subterminal position on the long arm of the satellitized chromosome pair Fig.

AAG 5which produced the clearest pattern of signals, was chosen as the diagnostic probe for identifying chromosomes and for analysing the physical mapping of the set of probes in multiple-target in situ experiments Fig. Other independent events of amplification of 5SrDNA repeats could be the origin of the third locus observed in the marinum accession GRA and in the Spanish material studied earlier by de Bustos et al. Canadian Journal of Genetics and Cytology.

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An autopolyploid origin is supported by a number of cytogenetic studies, including the analysis of C-banded karyotypes and the meiotic behaviour of hybrids Bothmer et al. Phylogenetic analyses of the diploid species of Hordeum Poaceae and a revised classification of the genus. Fluorescence microscopy and imaging Slides were examined using a Zeiss Axiophot epifluorescence microscope. Also as in marinumpAs1 showed a rich pattern of multiple signals of different intensity that was similar for different chromosomes, thus making their clear identification difficult Fig.

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July Mean Temperature Celsius: ACT 5 and ATC 5 returned very few signals, always of weak intensity, that could not be used as diagnostic landmarks data not shown. Phylogenetic tree including ideograms with the distribution of four repetitive sequences see colour key in the six accessions of Hordeum marinum examined.

It is noteworthy that no other diploid Hordeum species has a 5SrDNA locus on the long arm of its satellitized chromosomes de Bustos et al.

Assuming a monophyletic origin for the diploid cytotypes of H. Karyotypes were constructed designating chromosomes from 1 to 7 on the basis of similar chromosome morphology, size and the physical mapping of the probes in marinum karyotypes Fig.

Ecology An annual of barish places by the sea, on the trampled margins of dried-up pools and ditches in grazing marshes, on tracks and sea walls, and in the uppermost parts of saltmarshes; also, very locally, beside salt-treated roads inland. The usefulness of SSR sequences as chromosomal markers revealed by ND-FISH in different species, including several members of the tribe Triticeaehas been reported previously by our group Cuadrado et al.

To understand the genomic constitution of H. Published online Nov 5. Count of 10km squares in Great Britain: With respect to 5SrDNA, the common loci present in the diploid forms chromosomes 6 and 7 were probably present in their Xa genome common ancestor. Chromosome identities are indicated in white lettering.

Genome symbols in the Triticeae. Cytogenetic and Genome Research. In addition, as in diploid gussoneanuman interstitial site was found at a similar location on the long arm of a very submetacentric chromosome. Taxonomy of the H. Skip to main content. Genomic in situ hybridization GISH provides a useful cytogenetic means of identifying the parental origin of chromosomes present in hybrids and polyploids Cuadrado et al.