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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 166 (1989), S. 211-223 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Triticeae ; Hordeum brachyantherum ; H. californicum ; H. capense ; H. secalinum ; Morphometrics ; cluster analysis ; classificatory discriminant analysis ; canonical analysis ; sheared principal component analysis ; bootstrap validation ; identification key
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field collections and 296 herbarium sheets were examined for 27 morphometric variables. A priori species identifcation was based on geographical distribution except forH. californicum, a diploid species primarily occurring in California and differing from the much more widespread tetraploidH. brachyantherum that thrives in N. America and N.E. Asia;H. capense grows in S. Africa andH. secalinum mainly in Europe. Various cluster analyses were used followed by cluster recovery verification. Classificatory discriminant analysis and validation by the bootstrap yielded 85–90% overall total correct classification of the four species. Canonical analysis revealed thatH. californicum occupies an intermediate phenetic position among the other three distinct species. Factors of shape differences were unravelled and portrayed by shearing. A revised key to species was drawn up.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 183 (1992), S. 183-194 
    ISSN: 1615-6110
    Keywords: Poaceae ; Triticum aestivum ; 5S DNA sequences ; chromosomal5S Dna loci ; wheat evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A collection of 44 cloned 5S DNA units fromTriticum aestivum cv. ‘Chinese Spring’ were grouped into 12 sequence-types based on sequence similarity and the respective consensus sequences were then produced. The relationship between these 12 consensus sequences (T. aestivum S 1-S 8 andT. aestivum L 1-L 4), together with two clones sequenced byGerlach andDyer, and the 5S DNA consensus sequences from diploidTriticum spp. were then determined by numerical methods. Both phenetic and cladistic analyses were carried out. The following wheat 5S DNA sequences were found to group with respective sequences from diploidTriticum spp.:T. aestivum S 4, S 6 withT. tauschii S;T. aestivum S 3 withT. monococcum S andT. monococcum S-Rus 7;T. aestivum L 1 andT. aestivum L-G&D withT. speltoides L;T. aestivum L 2, L 3 withT. tauschii L;T. aestivum L 4 withT. monococcum L andT. monococcum L-Rus 12. The analyses suggested that 5 out of the 65S Dna loci present in wheat were identified at the sequence level. The locus that could not be identified in this analysis was the5S Dna-B 1 locus. A group ofT. aestivum sequences (T. aestivum S 1, S 7, S 8, S-G&D) were found to be distinct from the other 5S DNA sequences in the data base. The existence of the distinct group of 5S DNA sequences suggests that there is a gap in our current understanding of wheat evolution with respect to the5S Dna loci.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 183 (1992), S. 195-208 
    ISSN: 1615-6110
    Keywords: Poaceae ; Triticeae ; 5S DNA ; spacer ; phylogenetic inference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous studies have shown that two separate loci for 5S DNA sequences may exist within a species. Two size classes have been tentatively assigned in the ranges 327–468 bp (chromosome 1), and 469–500 bp (chromosome 5) and the entire data-base was subjected to various numerical taxonomic analyses. The results confirm the existence of two lineages of 5S DNA sequences represented by the two size classes.Hordeum vulgare is separate from the species known also asCritesion and, together withDasypyrum, occupy an intermediate position between the two size classes. The 5S DNA units fromTriticum spp. that have also been namedAegilops spp. in other classifications appear as a distinct group withinTriticum spp. at both loci. The consensus 5S DNA sequence fromPsathyrostachys is remote fromHordeum s.l. in contrast to opinions based on morphology. Other aspects are detailed and discussed, including the inadequacy of the computing methods used as well as the need for more data in view of the large amount of homoplasy. The merit of using the spacer for phylogenetic inference is also discussed.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 183 (1992), S. 249-264 
    ISSN: 1615-6110
    Keywords: Poaceae ; Oryza ; 5S DNA ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Relationships between 9Oryza species, covering 6 different genomes, have been studied using hybridization and nucleotide sequence information from the5S Dna locus. Four to five units of the major size class of 5S DNA in each species, 55 units in all, were cloned and sequenced. Both hybridization and sequence data confirmed the basic differences between the A and B, C, D genome species suggested by morphological and cytological data. The 5S DNA units of the A genome species were very similar, as were the ones from the B, C, and D genome-containing species. The 5S DNA ofO. australiensis (E genome) grouped with the B, C, D cluster, while the units ofO. brachyantha (F genome) were quite different and grouped away from all other species. 5S DNA units fromO. minuta, O. latifolia, O. australiensis, andO. brachyantha hybridized strongly, and preferentially, to the genomic DNA from which the units were isolated and hence could be useful as species/genome specific probes. The 5S DNA units fromO. sativa, O. nivara, andO. rufipogon provided A genome-specific probes as they hybridized preferentially to A genome DNA. The units fromO. punctata andO. officinalis displayed weaker preferential hybridization toO. punctata DNA, possibly reflecting their shared genome (C genome).
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  • 5
    ISSN: 1615-6110
    Keywords: Poaceae ; Triticeae ; Kengyilia ; Multivariate analysis ; generic limits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Based on 100 species representative of the four genera, we scored 290 herbarium specimens for a number of morphological characters. The data were subjected to canonical discriminant analysis using characters different from those in the identification key to these genera byBaum, Yen, andYang (1991). These characters collectively support the four groupsAgropyron, Kengyilia, Roegneria, andElymus as previously defined. The four groups are also supported by the linear discriminant function with an overall rate of 83% correct classification. Length of lemma awn was found to be an additional diagnostic character asAgropyron andKengyilia have lemma awns shorter than 5 mm, whereasRoegneria andElymus have longer lemma awns with very few exceptions. Length of glume awns is also a useful supplementary generic diagnostic.Agropyron andElymus have glume awns, whereas the majority of species ofKengyilia and more than half of the species ofRoegneria lack them. If a glume awn is present it is usually not longer than 1 mm.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 171 (1990), S. 205-220 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Secale ; Ribosomal DNA ; spacer subrepeats ; restriction fragment length polymorphism (RFLP) ; phenetic relationships
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variation in ribosomal DNA spacer length was analysed in 23 populations of 12Secale spp. by restriction enzyme analysis. Digestion of rDNA with Taq I endonuclease enzyme yields spacer fragments that include the subrepeat array and the non-repetitive region downstream of the array. Extensive spacer length variation existed in most species with Taq I fragment lengths ranging from 0.9–3.1 kb. These length variants have been attributed to the differences in number of 134 bp spacer subrepeats within rDNA arrays.S. silvestre was the only species to exhibit a unique spacer length variant of 0.9 kb and this was shown to result from the presence of an extra Taq I site in the spacer. rDNA spacer length frequencies were determined for the species. These frequencies were used to derive phenetic relationships between the species by numerical taxonomic methods. In plots constructed fromGower's distance matrices,S. silvestre appeared well separated from the major cluster consisting of the other species. On the basis of morphological and cytogenetic criteria,S. silvestre is considered the most ancient species. The rDNA data is consistent with this interpretation as it shows a clear differentiation ofS. silvestre from all the other species based on length and nucleotide sequence composition of the spacer region.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 174 (1991), S. 103-108 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Triticeae ; Kengyilia habahenensis ; spec. nova ; Taxonomy ; genome analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Kengyilia habahenensis, spec. nova, from the Altai mountains, China, is described morphologically and cytologically. It has 2n = 42 chromosomes, and the genome formula PYS.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Plant systematics and evolution 190 (1994), S. 97-111 
    ISSN: 1615-6110
    Keywords: Poaceae ; Hordeum ; Taxonomy ; logistic discrimination ; bootstrap validation ; multivariate analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hordeum caespitosum Scribner,H. jubatum L., andH. lechleri (Steudel)Schenck are very similar in appearance and therefore until recently were mostly not recognized as separate entities. The first two are tetraploid and natives to North America, but the second occurs naturally in eastern Siberia and has been introduced in Europe and South America and may become a cosmopolitan weed. The third is hexaploid and South American. This study analyses their morphological diversity by means of selected multivariate techniques in order to determine if there is justification to recognize them as three separate morphological species. Logistic discrimination, although based on a reduced set of characters, yielded the highest percent of correct assignments. A linear discriminant function is provided and validated by 100 bootstrap repeats. Canonical discriminant analysis indicated three groups. It is subsequently concluded that the three are separate morphological species. Although a linear discriminant function is given, a traditional identification key is provided based on the palea length and triad (the group of three spikelets at each rachis node) length.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 661-664 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 1691-1694 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis and the Crystal Structure Analysis of “Croconate Blue”, 1,2,4-Tris(dicyanomethylene)croconateReaction of the croconic acid diamide 9 with malononitrile in methanol leads to the condensation product 10, in which the two dimethylamino groups can be replaced by the anion of malononitrile to yield the potassium salt of the pseudooxocarbon dianion, so-called “Croconate Blue” 11a. Contrary to earlier findings, the structure of 11b, proved by X-ray diffraction, shows that the dicyanomethylene substituents of the dianion are located in 1,2,4-position of the five-membered ring.
    Notes: Bei der Reaktion des Krokonsäurediamids 9 mit Malondinitril in Methanol entsteht das Kondensationsprodukt 10, dessen Dimethylaminofunktionen durch das Anion des Malondinitrils substituiert werden unter Bildung des Kaliumsalzes des Pseudooxo-kohlenstoff-Dianions 11a, des sogenannten “Krokonat-Blau”. Im Gegensat zzu früheren Befunden beweist die Röntgenstrukturanalyse von 11b, daß die Dicyanmethylen-Substituenten des Dianions in 1,2,4-Position des Fünfringsystems angeordnet sind.
    Additional Material: 2 Ill.
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