ISSN:
1615-6110
Keywords:
Velloziaceae
;
Cytotaxonomy
;
mitotic chromosomes
;
interphase nuclei
;
heterochromatin
;
condensed euchromatin
;
C-banding
;
fluorochrome staining
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Chromosome number and other cytological features are reported from 35 species ofVelloziaceae, including several African and Brazilian populations. All analyzed species show areticulate interphase nuclei and prophase/prometaphase chromosomes with proximal early condensation. Most heteropycnotic blocks do not seem to correspond to heterochromatin since, at least inVellozia patens, they do not stain differentially after C-banding procedures. Regarding the chromosome number, three main groups could be identified. The first comprised diploid species of the generaNanuza, Vellozia and the Brazilian species ofXerophyta with 2n = 14 or 16; the second comprised tetraploid species with 2n = 34, and included all Brazilian species of subfam.Barbacenioideae; the third group, of hexaploid species, comprised the African representatives of the genusXerophyta. A single population ofVellozia, possibly of hybrid origin, had 2n ≅ 32. A basic number of x = 8 is proposed for the family. The karyological information supports the hypothesis that theVelloziaceae originated on the South American, rather than on the African continent.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00989209
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