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Küpfer, Philippe

Nom
Küpfer, Philippe
Affiliation principale
Fonction
Professeur honoraire
Email
philippe.kuepfer@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/301

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  • Publication
    Accès libre
    Seedcoat micromorphology of Impatiens (Balsaminaceae) from China
    (2005)
    Yuan, Yong-Ming
    ;
    Song. Yi
    ;
    Küpfer, Philippe 
    Seeds of 38 species of Impatiens mostly from south-western China were observed by scanning electron microscopy. High diversity was found in seedcoat micromorphology. Based on the structure and ornamentation of epidermal cells of the seedcoat, particularly the pattern of the arrangement of the cells and the degree of elevation of the anticlinal cell walls, four morphological types can be distinguished, viz, laevigate, granulate, reticulate and protrusive. The laevigate type and granulate type are unique, each occurring in only one species. The other two types are common and can be further divided into subdivisions according to the shape of the epidermal ornamentation of the seedcoat. Descriptions of seed size, shape and seedcoat types are summarized for the genus. Taxonomic and phylogenetic implications of the seedcoat micromorphology are also discussed, in comparison with the available gross morphological and molecular data.
  • Publication
    Accès libre
    Chromosome and breeding system evolution of the genus Mercurialis (Euphorbiaceae): implications of ITS molecular phylogeny
    (2002)
    Krähenbühl, M.
    ;
    Yuan, Y.-M.
    ;
    Küpfer, Philippe 
    The internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were amplified and sequenced from 19 samples representing all species of the genus Mercurialis and two outgroup species, Ricinus communis and Acalypha hispida. The length of ITS1 in the ingroups ranged from 223 to 246 bp and ITS2 from 210 to 218 bp. Sequence divergence between pairs of species ranged from 1.15% to 25.88% among the ingroup species in the combined data of ITS1 and ITS2. Heuristic phylogenetic analyses using Fitch parsimony on the combined data of ITS1 and ITS2 with gaps treated as missing generated 45 equally parsimonious trees. The strict consensus tree was principally concordant with morphological classification. Within the genus, the ITS sequences recognised two main infrageneric clades: the M. perennis complex including three Eurasian stoloniferous species (M.␣leiocarpa, M. ovata and M. perennis) and the western Mediterranean group including eight both annual and perennial species. Of the western Mediterranean clade, the annual and perennial species grouped respectively into two different groups, and the annual life form is revealed as a synapomorphic character derived from perennial, whereas in the Eurasian clade ITS phylogeny suggested M. leiocarpa as basal clade sister to M.␣perennis and M. ovata. ITS phylogeny failed to resolve the relationships among the different cytotypes of M. ovata and M. perennis. ITS phylogeny also suggested rapid karyotypic evolution for the genus. The karyotypic divergence among the perennial species of western Mediterranean region did not corroborate the nucleotide sequence divergence among the species. Optimisation of chromosome numbers onto the ITS phylogeny suggested x=8 to be the ancestral basic chromosome number of the genus. ITS phylogeny confirmed that the androdioecy of M. ambigua is derived from dioecy. The nucleotide heterozygosity and additivity in ITS sequences clearly confirm the interspecific hybridisation in the genus Mercurialis.
  • Publication
    Accès libre
    The monophyly and rapid evolution of Gentiana sect. Chondrophyllae Bunge s.l. (Gentianaceae): evidence from the nucleotide sequences of the internal transcribed spacers of nuclear ribosomal DNA
    (1997)
    Yuan, Yong-Ming
    ;
    Küpfer, Philippe 
    The nucleotide sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA of 24 representative species of sect. Chondrophyllae s.l. have been determined and analysed phylogenetically, together with some species of other sections of the genus Gentiana. The ITS sequences strongly support the monophyly of the sect. Chondrophyllae s.l. as a whole complex including various different dysploid cytotypes. Species, such as G. boryi and G. pyrenaica, that had been split into distinct genera by some cytotaxonomists have been proven to be closely related. However, the ITS sequences do not provide sufficient information to make a robust estimation of the phylogenetic relationships among the closely related species and dysploid cytotypes of the complex, beyond recognizing their monophyly and rapid evolution.