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The karyology of some Taraxacum species from alpine regions of Europe

Author:
RICHARDS, A.J.
Source:
Botanical journal of the Linnean Society 1972 v.65 no.1 pp. 47-59
ISSN:
0024-4074
Subject:
Taraxacum, chromosomes, karyotyping, Europe
Abstract:
The karyotypes of 18 samples assigned to 13 agamospecies in Taraxacum are described. The species are classified among six sections; Eiythrosperma Lindb. f., Vulgaria Dahlst., Alpestria v. Soest, Alpina Hagl., Fontana v. Soest and Cucullata v. Soest, all from alpine localities in Europe. No previous cytological work is known for agamospecies in the last four sections. Two small chromosome types and the occurrence of accessory chromosomes are described for the first time in Taraxacum. Sibling karyotypes were found to be invariable, but extensive karyotypic variation was found between samples, even intraspecifically. Karyotypes were compared by means of a “karyotype similarity index”. Samples with a high overall similarity tended to have smaller chromosomes. Eight species exhibited regular chromosome sets, the remainder being irregular. The nature of the origin of the latter is discussed in relation to the origin of agamospecies in the genus.
Agid:
422494