caa a22 4500 477038786 CHVBK 20180405111311.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00985241 doi (NATIONALLICENCE)springer-10.1007/BF00985241 Cytological variation and evolution within Pelargonium section Hoarea ( Geraniaceae ) [Elektronische Daten] [Mary Gibby, Silke Hinnah, Elizabeth Marais, Focke Albers] Chromosome numbers of 65 species of sect.Hoarea have been determined. These show three basic chromosome numbers, x = 11, 10 and 9. Only a few species are tetraploid. In five species both diploid and tetraploid cytotypes are reported. Several cases of deviations in chromosome numbers and cytological abnormalities were found, most of these being related to the presence of B chromosomes that occur in eight species. Evidence is presented to suggest that the basic chromosome numbers of x = 10 and x = 9 are derived from x = 11 by centric fusion. Although variation in basic chromosome number withinPelargonium has been the subject of detailed study, this is the first time that evidence has been found for a mechanism of change in basic number, that of centric fusion by Robertsonian translocation. For the species of sect.Hoarea with x = 9, where the evidence for Robertsonian translocation is greatest, this process has probably taken place quite recently. In contrast to results from other sections of the genusPelargonium, the three different basic numbers of sect.Hoarea do not contradict its delimitation as a natural taxon. Springer-Verlag, 1996 Pelargonium nationallicence sect. Hoarea nationallicence Chromosomes nationallicence B chromosomes nationallicence Robertsonian translocation nationallicence centric fusion nationallicence evolution nationallicence systematics nationallicence Gibby Mary Department of Botany, The Natural History Museum, Cromwell Road, SW7 5BD, London, UK aut Hinnah Silke Institut für Botanik, Westfälische Wilhelms—Universität, Schloßgarten 3, D-48149, Münster, Germany aut Marais Elizabeth Department of Botany, University of Stellenbosch, 7599, Matieland, South Africa aut Albers Focke Institut für Botanik, Westfälische Wilhelms—Universität, Schloßgarten 3, D-48149, Münster, Germany aut Plant Systematics and Evolution Springer-Verlag 203/1-2(1996-03-01), 111-142 0378-2697 203:1-2<111 1996 203 606 https://doi.org/10.1007/BF00985241 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00985241 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gibby Mary Department of Botany, The Natural History Museum, Cromwell Road, SW7 5BD, London, UK aut NATIONALLICENCE 700 1- Hinnah Silke Institut für Botanik, Westfälische Wilhelms—Universität, Schloßgarten 3, D-48149, Münster, Germany aut NATIONALLICENCE 700 1- Marais Elizabeth Department of Botany, University of Stellenbosch, 7599, Matieland, South Africa aut NATIONALLICENCE 700 1- Albers Focke Institut für Botanik, Westfälische Wilhelms—Universität, Schloßgarten 3, D-48149, Münster, Germany aut NATIONALLICENCE 773 0- Plant Systematics and Evolution Springer-Verlag 203/1-2(1996-03-01), 111-142 0378-2697 203:1-2<111 1996 203 606 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer