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  • Publication
    Accès libre
    Chromosomal evolution of Gentiana and Jaeschkea (Gentianaceae), with further documentation of chromosome data for 35 species from western China
    (1998)
    Yuan, Yong-Ming
    ;
    ;
    Zeltner, Louis
    Chromosome 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.