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Küpfer, Philippe
Nom
Küpfer, Philippe
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Professeur honoraire
Email
philippe.kuepfer@unine.ch
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- PublicationAccès libreCytogeography of Gentianaceae–Exaceae in Africa, with a special focus on Sebaea: the possible role of dysploidy and polyploidy in the evolution of the tribe(2008)
; ; Mansion, GuilhemUnlike other tribes of Gentianaceae, Exaceae have so far received little attention regarding their karyological evolution. Indeed, only 35 chromosome number counts (19 species) have been referenced to date, representing only a negligible fraction of the tribal diversity. In this paper, we performed an intensive chromosome count on material collected in the field (South and central Africa, plus Madagascar), encompassing 155 populations and c. 60 species from four genera of Exaceae, including Exacum, Ornichia, Sebaea and Tachiadenus. Fifty nine species (14 Exacum, one Ornichia, 42 Sebaea and two Tachiadenus) were examined for the first time, revealing a broad set of chromosome numbers (2n = 18, 28, 32, 36, 42, 56) and the occurrence of polyploid systems within Exacum and Sebaea. These results allow us to postulate x = 7, 8 or 9 as possible base chromosome numbers for Exaceae and emphasize the importance of both dysploidy and polyploidy processes in the evolution of the tribe. Finally, chromosome numbers appear to be associated to some morphological or geographical traits, suggesting new systematic combinations and likely active speciation patterns in the group. - PublicationAccès libreChromosomal evolution of Gentiana and Jaeschkea (Gentianaceae), with further documentation of chromosome data for 35 species from western China(1998)
; Zeltner, LouisChromosome numbers were recorded for 63 populations of 34 species belonging to the genus Gentiana from the high altitude regions of western China. Counts for 22 species were reported for the first time and new numbers were found for G. heleonastes (2n = 36), G. prattii (2n = 20) and G. pseudoaquatica (2n = 40). Incorporating previous data, a complete series of gametic chromosome numbers from n = 6 to 24 and 26 was established for the genus, suggesting rapid karyotypic evolution by a combination of dysploidy and polyploidy. The cytotype 2n = 20 is proposed as the ancestral type in sect. Chondrophyllae s. l. The chromosome number 2n = 16 was found for Jaeschkea microsperma for the first time which, with previous reports of 2n = 18, 20 and 22, indicates that Jaeschkea is a typically dysploid genus. - PublicationAccès libreCytotaxonomic notes on the tribe Helieae (Gentianaceae)
; A survey of all known chromosome counts of gentian tribe Helieae are presented including new reports for ten species. Amongst the novelties are four genera of the Gentianaceae that are reported for the first time, Calolisianthus and Helia (both Helieae), and Schultesia and Zygostigma (both Chironieae). In the Helieae, our results reinforce the hypothesis of Weaver 1969 that two ploidy series occur in the tribe, one polyploid based on n = 20 and one dysploid based on n = 21. The basal chromosome number for the Helieae remains to be determined.