Abstract
Chromosome studies have been conducted on the long-term callus cultures of threeAllium species:A. porrum (2n=32),A. tuberosum (2n=32) andA. fistulosum (2n=16). In cultures ofA. fistulosum several interesting cytological abnormalities were observed. They included direct elimination of chromatin from nuclei, multiple chromosome fusions and formation of polycentric and megachromosomes. The rate of abnormalities increased with the time of culture.
Allium fistulosum may provide an excellent model system to analyse cytogenetic and molecular aspects of callus-induced genomic changes and, thus, somaclonal variation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bayliss, M. W., 1980. Chromosomal variation in plant tissues culture. Int. Rev. Cytol., Suppl. 11a: 113–114.
Burns, J. A. & D. U. Gerstel, 1967. Flower colour variegation and instability of a block of heterochromatin inNicotiana. Genetics 57: 155–167.
Burns, J. A. & D. U. Gerstel, 1969. Consequences of spontaneous breakage of heterochromatic chromosome segments inNicotiana hybrids. Genetics 63: 427–439.
Burns, J. A. & D. U. Gerstel, 1973. Formation of megachromosomes from heterochromatic blocks ofNicotiana tomentosiformis. Genetics 75: 497–502.
Coates, D. J., 1980. B chromosomes inStylidium crossocephalum (Angiospermae: Stylidiaceae). Chromosoma 77: 347–358.
Deumling, B. & L. Clermont, 1989. Changes in DNA content and chromosomal size during cell culture and plant regeneration ofScilla siberica; selective chromatin diminution in response to environmental conditions. Chromosoma 97: 439–448.
Geber, G. & D. Schweizer, 1988. Cytochemical heterochromatin differentiation inSinapsis alba (Cruciferae) using a simple air-drying technique for producing chromosome spreads. Pl. Syst. Evol. 158: 97–106.
Gerstel, D. U. & J. A. Burns, 1972. Megachromosomes in hybrids involvingNicotiana tomentosiformis andN. tabacum. Genetics 71: 19.
Gerstel, D. U. & J. A. Burns, 1976. Enlarged euchromatic chromosomes (‘megachromosomes’) in hybrids betweenNicotiana tabacum andN. plumbaginifolia. Genetica 46: 139–153.
John, B., R. Appels & N. Contreras, 1986. Population cytogenetics ofAtractomorpha similis. II. Molecular characterisation of the distal C-band polymorphisms. Chromosoma 94: 45–58.
Murashige T. & F. Skoog, 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiologia Pl. 15: 473–497.
Nagl, W., 1983. Heterochromatin elimination in the orchidDendrobium. Protoplasma 118: 234–237.
Schwarzachter, T., P. Ambros & D. Schweizer, 1980. Application of Giemsa banding to orchid karyotype analysis. 134: 293–297.
Vig, B. K. & B. T. Richards, 1992. Formation of primary constriction and heterochromatin in mouse does not require minor satellite DNA. Exp. Cell Res. 201: 292–298.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Joachimiak, A., Przywara, L., Ilnicki, T. et al. Megachromosomes in tissue culture ofAllium . Genetica 90, 35–40 (1993). https://doi.org/10.1007/BF01435176
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01435176