ISSN:
1432-2242
Keywords:
Nicotiana
;
Chromosomal instability
;
Abnormal mitoses
;
Polyteny
;
Tumor
;
Organization
;
Regulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Callus cultures of Nicotiana glauca, N. langsdorffii and of their tumor-forming hybrid plants contained a high frequency of cells with irregular chromosome numbers and chromosome aberrations (hypo-, hyper-, polyploid, aneuploid cells; bridges, polytene, broken, fragmented chromosomes, megachromosomes, etc.). Meristematic cells of shoot tips regenerated from the same cultures contained only regular chromosome numbers with normal chromosome structures. Variability in chromosome numbers is a consequence of abnormal mitoses. The data suggest genome segregation in the cultures. Cytological instability appears to be independent of genome segregation composition, genotype, tumorous condition, hormonal requirement and level of ploidy. The karyotype stability of the cultures is only dependent on the degree of organization of tissues and is regulated by factors involved in the control mechanisms of organizational processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00305989
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