The cytology of Brachycome. I. The subgenus Eubrachycome. a general survey

@article{Smithwhite1970TheCO,
  title={The cytology of Brachycome. I. The subgenus Eubrachycome. a general survey},
  author={S Smith-white and Cristina R. Carter and Helen M. Stace},
  journal={Australian Journal of Botany},
  year={1970},
  volume={18},
  pages={99-125}
}
Chromosome number determinations and cytological observations are reported for 37 recognized taxonomic species and varieties, and for a number of undescribed species and chromosome races in Eubrachycome. Additionally, chromosome numbers are reported for six species of Metabrachycome and two species of related genera. A wide range of numbers has been found. It is inferred that x = 9 is the primitive base number in the group. Eubrachycome has used various modes of chromosomal change, including… 
The cytology of Brachycome lineariloba
TLDR
The frequencies and behaviour of two types of accessory chromosome in Brachycome lineariloba species A (n=2) are reported, and loss must be balanced against mechanisms tending to increase B frequency.
The B chromosomes in Brachycome
This review presents a historical account of studies of B chromosomes in the genus Brachycome Cass. (synonym: Brachyscome) from the earliest cytological investigations carried out in the late 1960s
Molecular systematics of Australian Calotis (Asteraceae: Astereae)
TLDR
The elaborated pappus and surface structures of cypsela, and life form of species seem to be homoplasous with multiple origins in the evolutionary history of the lineage, which is greater in perennials than in annuals within the genus Calotis.
Cytoevolutionary patterns inRutaceae
TLDR
It appears that diploid x = 18 is ancestral in the Rutaceae and the morphologically advancedCitroideae are invariant for x = 9 and may be a product of dysploid reduction.
Chromosome studies in New Zealand species of Brachyscome (Asteraceae)
Abstract Chromosome numbers were determined for plants of five species and seven additional entities of uncertain taxonomic status of Brachyscome. We confirmed the chromosome numbers of several
The Cytology of Brachyscome Cass. (Asteraceae: Astereae). II. Hybridisation Between B. goniocarpa (N = 4) and B. dichromosomatica (N = 2)
TLDR
Cytological investigations showed that the total length of mitotic metaphase chromosomes for the B. dichromosomatica haploid set was 1.33 times that of the B goniocarpa set, suggesting that the current placement of the two taxa in different superspecies is not warranted.
Chromosomal Evolution in the Genus Brachyscome (Asteraceae, Astereae): Statistical Tests Regarding Correlation Between Changes in Karyotype and Habit Using Phylogenetic Information
TLDR
The correlations between the dysploidal reduction in chromosome number and the increases in mean chromosome length, length heterogeneity and asymmetry in karyotype can be attributed to this mode of chromosomal change.
Internal transcribed spacer sequence analyses indicate cytoevolutionary patterns within Brachycome Cass. (Asteraceae)
TLDR
The sequences of the Internal Transcribed Spacer regions (ITS1 and ITS2) within the genes coding for cytoplasmic ribosomal RNAs on the A chromosome complement of 34 members of the higher plant genus Brachycome have been compared to support the suggestion that the number of chromosomes reduced in several independent Brachy Come lineages during speciation.
Molecular phylogeny ofBrachycome (Asteraceae)
TLDR
Intrageneric relationships in the genusBrachycome were investigated by the comparison of nucleotide sequences of the chloroplast genematK, and circumscription of superspecies based primarily on fruit morphology is not fully supported.
DNA CONTENT OF SEVEN SPECIES OF ASTEREAE AND ITS SIGNIFICANCE TO THEORIES OF CHROMOSOME EVOLUTION IN THE TRIBE
TLDR
The results show that A. hydrophilus and M. brevilingulata, with a chromosome number of n = 9, have less nuclear DNA than other closely related species which are either n = 4 or n = 5.
...
...

References

SHOWING 1-10 OF 22 REFERENCES
THE INDEPENDENT ANEUPLOID ORIGIN OF TWO SPECIES OF CHAENACTIS (COMPOSITAE) FROM A COMMON ANCESTOR
TLDR
The purpose of this paper is to present a unique example in Chaenactis (Compositae) in which the cytogenetical evidence indicates beyond reasonable doubt that an extant species of relatively mesic habitats, C. glabriuscula DC.
CATASTROPHIC SELECTION AS A FACTOR IN SPECIATION
TLDR
A study of species relationships in the genus Clarkia has led me to the conclusion that rapid speciation, involving an abrupt shift in adaptive mode and accompanied by barriers to gene exchange, represents the normal mode of speciation.
Two new Australian species of Brachycome Cass. (Compositae)
  • G. L. Davis
  • Biology
    Muelleria: An Australian Journal of Botany
  • 1955
...
...