Interspecific hybridization with Hordeum bulbosum and development of hybrids and haploids

Subrahmanyam, N.C. and Bothmer, R. von, 1987. Interspecific hybridization with Hordeum bulbosum and development of hybrids and haploids. - Hereditas 106: 119-127. Lund, Sweden. ISSN 001-0661. Received May 2, 1986.A total of 64 interspecific crossing combinations with H. bulbosum (2x and 4x) were attempted. The maximum seed set was generally very high. Progeny was obtained in 19 combinations with diploid and 13 combinations with tetraploid H. bulbosum. As a result of selective chromosome elimination, haploids were recorded in 7 interspecific combinations with diploid and 7 with tctraploid H. bulbosum. There are 7 new haploid-producing combinations, viz. H. cordobense monohaploids, H. marinum mono- and dihaploids. and H. brevisubularum di- and trihaploids in crosses with H. bulbosum (4x), H. capense dihaploids and H. murinum dihaploids with H. bulbosum (2x). The theory of a hierarchical chromosome elimination system is strengthened by the present results.Roland yon Bothmer, Department of Crop Genetics and Breeding, Swedish University of Agricultural Sciences, S-268 00 Svalov, Sweden

Genome Symbols in the Triticeae (Poaceae)

A system for the application of nuclear genome symbols in the tribe Triticeae is proposed. It is based mainly on prevailing symbols. In agreement with this, the system uses individual upper case letters as symbols in the first place. Since the number of basic nuclear genomes in the Triticeae exceeds the number of single letters in the Roman alphabet, some basic genomes are designated with an upper case letter followed by a lower case letter, e.g. Ns for the genome of Psathyrostachys. Superscripts in small letters are used when modified versions of a basic genome are referred to, e.g. HP for the genome found in Hordeum pusillum. Unknown or equivocally identified genomes are designated by X followed by a lower case letter, e.g. Xu for Hordeum murinum. Underline of the relevant genome symbol can be used to indicate the origin of the cytoplasm

Characterization of genetic diversity in core collection accessions of wild barley, Hordeum vulgare ssp. spontaneum

Publisher's version/PDFGenetic variability in the 143 core accessions of wild barley, Hordeum vulgare ssp. spontaneum, was assessed by allozyme analysis. A total of 34 alleles were detected at ten isozyme loci. All loci were polymorphic except Pgd-1, which was monomorphic. Est-2 and Est-4 were the most diverse loci, with genetic diversity values of 0.747 and 0.686, respectively. The comparison of the results with those of previous studies indicates that all alleles occurring in cultivated and wild barley are observed in this set of the wild Barley Core Collection. Only one allele (Pgd-1 Tj ) was absent. It is noteworthy that one new allele at the Ndh-2 locus and another new allele at Aco-2 locus were first detected in the present study. Nine of the 34 alleles were rare and detected only in one to four accessions. The genetic similarities among the 143 accessions ranged from 0.18 to 1.00. Data analysis based on clustering and principal coordinate analysis showed that a high level of genetic variability exists in this set of core accessions, and indicated that some duplication probably exists in this set core based on the present study

Linear precision for toric surface patches

We classify the homogeneous polynomials in three variables whose toric polar linear system defines a Cremona transformation. This classification also includes, as a proper subset, the classification of toric surface patches from geometric modeling which have linear precision. Besides the well-known tensor product patches and B\'ezier triangles, we identify a family of toric patches with trapezoidal shape, each of which has linear precision. B\'ezier triangles and tensor product patches are special cases of trapezoidal patches

Report of a Working Group on Barley: Fifth meeting, 10-12 July 1997, Alterode/Gatersleben, Germany

These proceedings outline the discussions and recommendations made at the working group and contains the collection of presented papers from the meeting. Main topics of discussion include the European Barley Database (EBDB), the status of national collections, sharing responsibilities for conservation and promoting the use of barley genetic resources

Report of a Working Group on Barley: Sixth meeting, 3 December 2000, Salsomaggiore, Italy

These proceedings outline the discussions and recommendations made at the working group and contains the collection of presented papers from the meeting. Main topics of discussion include the European Barley Database (EBDB), the status of national collections, sharing responsibilities for conservation and promoting the use of barley genetic resources

Identification of the chromosome complement and the spontaneous 1R/1V translocations in allotetraploid Secale cereale × Dasypyrum villosum hybrids through cytogenetic approaches

Genome modifications that occur at the initial interspecific hybridization event are dynamic and can be consolidated during the process of stabilization in successive generations of allopolyploids. This study identifies the number and chromosomal location of ribosomal DNA (rDNA) sites between Secale cereale, Dasypyrum villosum, and their allotetraploid S. cereale × D. villosum hybrids. For the first time, we show the advantages of FISH to reveal chromosome rearrangements in the tetraploid Secale × Dasypyrum hybrids. Based on the specific hybridization patterns of ribosomal 5S, 35S DNA and rye species-specific pSc200 DNA probes, a set of genotypes with numerous Secale/Dasypyrum translocations of 1R/1V chromosomes were identified in successive generations of allotetraploid S. cereale × D. villosum hybrids. In addition we analyse rye chromosome pairs using FISH with chromosome-specific DNA sequences on S. cereale × D. villosum hybrids

"I did not intend to stop. I just could not stand cigarettes any more." A qualitative interview study of smoking cessation among the elderly

<p>Abstract</p> <p>Background</p> <p>Every year, more than 650,000 Europeans die because they smoke. Smoking is considered to be the single most preventable factor influencing health. General practitioners (GP) are encouraged to advise on smoking cessation at all suitable consultations. Unsolicited advice from GPs results in one of 40-60 smokers stopping smoking. Smoking cessation advice has traditionally been given on an individual basis. Our aim was to gain insights that may help general practitioners understand why people smoke, and why smokers stop and then remain quitting and, from this, to find fruitful approaches to the dialogue about stopping smoking.</p> <p>Methods</p> <p>Interviews with 18 elderly smokers and ex-smokers about their smoking and decisions to smoke or quit were analysed with qualitative content analysis across narratives. A narrative perspective was applied.</p> <p>Results</p> <p>Six stages in the smoking story emerged, from the start of smoking, where friends had a huge influence, until maintenance of the possible cessation. The informants were influenced by "all the others" at all stages. Spouses had vital influence in stopping, relapses and continued smoking. The majority of quitters had stopped by themselves without medication, and had kept the tobacco handy for 3-6 months. Often smoking cessation seemed to happen unplanned, though sometimes it was planned. With an increasingly negative social attitude towards smoking, the informants became more aware of the risks of smoking.</p> <p>Conclusion</p> <p>"All the others" is a clue in the smoking story. For smoking cessation, it is essential to be aware of the influence of friends and family members, especially a spouse. People may stop smoking unplanned, even when motivation is not obvious. Information from the community and from doctors on the negative aspects of smoking should continue. Eliciting life-long smoking narratives may open up for a fruitful dialogue, as well as prompting reflection about smoking and adding to the motivation to stop.</p