Summary
Tetraploid clones were isolated from a predominantly diploid culture line ofDaucus carota by plating alone or after colchicine treatment. Although individually these tetraploid clones had similar growth rates to the diploid culture, they were progressively eliminated from mixtures with the diploid line. As the diploid culture line always contained a low frequency of tetraploids, the selective elimination of tetraploids must have been balanced by their continuous production. The frequency of endoreduplication detected was too low to maintain the equilibrium frequency of tetraploids and it is proposed that polyploidisation also occurred by endomitosis. The mean frequency of tetraploid metaphases within the diploid culture line was reduced by shortening the interval between subcultures from 14 to 7 days. This 7-day regime also eliminated linear growth and stationary phase periods, but did not alter the maximum growth rate or mitotic index of the culture. It is argued that the change in mean tetraploid metaphase frequency is indicative of a change in the number of tetraploid cells within the culture, brought about by an alteration in the equilibrium between production and elimination of tetraploid cells.
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References
Bayliss, M. W., 1976: Variation of cell cycle duration within suspension cultures ofDaucus carota and its consequence for the induction of ploidy changes with colchicine. Protoplasma88, 279–285.
—, 1975 a: The effects of growthin vitro on the chromosome complement ofDaucus carota L. suspension cultures. Chromosoma51, 401–411.
—, 1975 b: The duration of the cell cycle ofDaucus carota in vivo andin vitro. Exp. Cell Res.92 (1), 31–38.
—, 1977: Factors affecting the frequency of tetraploid cells in a predominantly diploid suspension culture ofDaucus carota. Protoplasma92, 109–115.
—, 1977: The causes of competition between two cell lines ofDaucus carota in mixed culture. Protoplasma92, 117–127.
Butcher, N., A. K. Sogeke, andI. C. Tommerup, 1975: Factors influencing changes in ploidy and nuclear DNA levels in cells from normal, crown-gall and habituated cultures ofHelianthus anuus L. Protoplasma86, 295–308.
Clements, W. M., 1964: Stability of chromosome numbers in tissue cultures of alfalfa,Medicago sativa. Amer. J. Bot.51, 670.
Cooper, L. S., D. C. Cooper, A. C. Hildebrandt, andA. J. Riker, 1964: Chromosome numbers in single cell clones of tobacco tissue. Amer. J. Bot.51, 284–290.
Mansfield, K. J., 1973: The isolation of clones by single cell plating. M. Sci. Thesis, University of Sheffield, U.K.
Murashige, T., andF. Skoog, 1962: A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant.15, 473–497.
Partenen, C. M., 1963: Plant tissue culture in relation to developmental cytology. Int. Rev. Cytol.15, 215–243.
Sacristan, M. D., 1971: Karyotypic changes in callus cultures from haploid and diploid plants ofCrepis capillaris (L.) Wallr. Chromosoma33, 273–283.
—, 1967: Auxin-autotrophie und Chromosomenzahl. Molec. gen. Genet.99, 311–321.
Salmia, M. A., 1975: Cytological studies on tissue culture ofPinus cembra. Physiol. Plant.33 (1), 58–61.
Smith, S. M., andH. E. Street, 1974: The decline of embryogenic potential as callus and suspension cultures of carrot (Daucus carota) are serially subcultured. Ann. Bot.38, 223–241.
Singh, B. D., 1975: Evolution of dominant karyotypes ofHaplopappus gracilis cells culturedin vitro. Caryologia28 (1), 29–37.
—, andB. L. Harvey, 1975: Cytogenetic studies onHaplopappus gracilis cells cultured on agar and in liquid media. Cytologia40 (2), 347–354.
— —, 1975: Selection for diploid cells in suspension cultures ofHaplopappus gracilis. Nature253, 453.
— —,K. N. Kao, andR. A. Miller, 1975: Karyotypic changes and selection pressure inHaplopappus gracilis suspension cultures. Canad. J. Genet. Cytol.17, 109–116.
— — — —, 1972: Selection pressure in cell populations ofVicia hajastana culturedin vitro. Canad. J. Genet. Cytol.14, 65–70.
Sunderland, N., 1973: Plant tissue and cell culture (Street, H. E., ed.), pp. 161–190. Oxford: Blackwell.
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Bayliss, M.W. Factors affecting the frequency of tetraploid cells in a predominantly diploid suspension culture ofDaucus carota . Protoplasma 92, 109–115 (1977). https://doi.org/10.1007/BF01280203
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DOI: https://doi.org/10.1007/BF01280203