Chromosome numbers, nuclear DNA content, and polyploidy in Consolea (Cactaceae), an endemic cactus of the Caribbean Islands.

@article{NegrnOrtz2007ChromosomeNN,
  title={Chromosome numbers, nuclear DNA content, and polyploidy in Consolea (Cactaceae), an endemic cactus of the Caribbean Islands.},
  author={Vivian Negr{\'o}n-Ort{\'i}z},
  journal={American journal of botany},
  year={2007},
  volume={94 8},
  pages={
          1360-70
        }
}
Polyploidy, an important mechanism of plant evolution, was investigated in Consolea, an endemic Caribbean opuntioid genus represented by nine subdioecious species with very narrow distributions, including species classified as rare or threatened. Standard chromosome counting and flow cytometric analyses were used to determine chromosome numbers and ploidy of each taxon. Compared to the base number (x = 11), the mitotic and meiotic counts indicated that there are seven hexaploid (2n = 66) and… 

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References

SHOWING 1-10 OF 74 REFERENCES

Nuclear genome size and karyotype analysis in Mammillaria species (Cactaceae)

The Mammillaria species exhibited an endopolyploidy pattern with 2–16 C DNA content in the stem parenchyma, which may give them alternative strategies for adaptation in arid environments.

Interspecific variation of nuclear DNA and structural changes in meiotic and mitotic chromosome in some species of Mammillaria (Cactaceae)

SUMMARYMitotic and meiotic chromosome number, karyotype, chiasma frequency in pollen mother cells, Interphase Nuclear Volume (INV) and nuclear DNA amounts in 12 species of Mammillaria revealed

Determination of ploidy and nuclear DNA content in populations of Atriplex halimus (Chenopodiaceae)

For certain populations having morphologies intermediate between those considered typical of these two subspecies, nuclear DNA contents showed them to be tetraploid, with greater values in the more easterly populations.

Cytophotometric Estimation of 4C DNA Content and Chromosome Analysis in Four Species of Astrophytum Lem. of the Family Cactaceae

The structural alterations in the chromosomes as well as loss or addition of highly repetitive sequences in the genome caused variations in the nuclear DNA at interspecific level indicating a micro-change of nuclear material during evolution.

Interspecific Variations of Nuclear DNA Content and Karyotype Diversity in Ferocactus

The structural alterations in the chromosomes as well as loss or addition of highly repetitive sequences in the genome suggest variations in the nuclear DNA at interspecific level during macro- and micro-evolution of the species.

Studies on Nuclear DNA and Meiotic Chromosomes in 8 Species on Mammillaria

Meiotic studies of Pollen Mother Cell (PMCs) and 4C DNA content from root tip cells of 8 species of Mammillaria of the family Cactaceae revealed significant interspecific variations in the genome, leading to genetic drift among the species.

Characterizing polyploidy in Arabidopsis lyrata using chromosome counts and flow cytometry

Chromosome counts in this study confirmed ploidy expectations for all populations examined, and the need to calibrate DNA content measures with chromosome counts was demonstrated by a deviation from the expected 2:1 ratio between tetraploid and diploid values among European populations.

DNA content and ploidy determination of bromegrass germplasm accessions by flow cytometry

The NPGS bromegrass germplasm could be enhanced by collections from western and central Europe, the Middle East, and China.

Cytomixis and its possible evolutionary role in a Kuwaiti population of Diplotaxis harra (Brassicaceae)

During a cytotaxonomical study of a Kuwaiti diploid population of Diplotaxis harra (Forssk.) Boiss, cytomixis and aneuploidy were found in 1.5% and 7.8% of the pollen mother cells (PMCs), respectively.

Genome downsizing in polyploid plants

The results suggest that loss of DNA following polyploid formation, or genome downsizing, may be a widespread phenomenon of considerable biological significance and the nature of the evolutionary forces that may be driving DNA loss are discussed.
...