Cytological studies in some South Indian species of Carex.

Nijalingappa, B. H. M.; Bai, Da-Quan

doi:10.1508/cytologia.55.373

Cited by 3 publications

(1 citation statement)

References 19 publications

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“…Following the seminal work of Heilborn (1924Heilborn ( , 1928Heilborn ( , 1932, several researchers have undertaken genus-wide studies of chromosome variation (notably Tanaka, 1937Tanaka, , 1939Tanaka, , 1940aWahl, 1940;Tanaka, 1941aTanaka, , b, 1948Tanaka, , 1949Davies, 1956;Hoshino, 1981;Löve, 1981), and numerous other researchers have counted chromosome numbers in one or a few sections or geographic areas (e.g., Faulkner, 1972;Whitkus, 1981;Löve, 1982;Cayouette & Morisset, 1986a;Nijalingappa & Bai, 1990;Luceño, 1993;Rothrock & Reznicek, 1996). To date, approximately 16 percent of described Carex species have been sampled (Roalson, 2008).…”

Section: Systematic Distribution Of Chromosome Numbersmentioning

confidence: 99%

The Evolution of Chromosome Arrangements in Carex (Cyperaceae)

2008

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Sedges (Carex: Cyperaceae) exhibit remarkable agmatoploid chromosome series between and within species. This chromosomal diversity is due in large part to the structure of the holocentric chromosomes: fragments that would not be heritable in organisms with monocentric chromosomes have the potential to produce viable gametes in organisms with holocentric chromosomes. The rapid rate of chromosome evolution in the genus and high species diversification rate in the order (Cyperales Hutch., sensu Dahlgren) together suggest that chromosome evolution may play an important role in the evolution of species diversity in Carex. Yet the other genera of the Cyperaceae and their sister group, the Juncaceae, do not show the degree of chromosomal variation found in Carex, despite the fact that diffuse centromeres are a synapomorphy for the entire clade. Moreover, fission and fusion apparently account for the majority of chromosome number changes in Carex, with relatively little duplication of whole chromosomes, whereas polyploidy is relatively important in the other sedge genera. In this paper, we review the cytologic and taxonomic literature on chromosome evolution in Carex and identify unanswered questions and directions for future research. In the end, an integration of biosystematic, cytogenetic, and genomic studies across the Cyperaceae will be needed to address the question of what role chromosome evolution plays in species diversification within Carex and the Cyperaceae as a whole.

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Section: Systematic Distribution Of Chromosome Numbersmentioning

confidence: 99%

The Evolution of Chromosome Arrangements in Carex (Cyperaceae)

2008

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A Synopsis of Chromosome Number Variation in the Cyperaceae

Roalson

2008

Bot. Rev

112

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The Cyperaceae are well known for having a large amount of variation in chromosome numbers both within and among genera. Most of this variation has been previously attributed to agmatoploid or qualitative aneuploid chromosome number change. To date there have been 4,231 reported chromosome number counts in the family. Despite the large number of counts made, they only represent approximately 16% of the species currently recognized. These counts are here presented in an indexed list with standardized nomenclature following a draft copy of the World Checklist of Cyperaceae. Additionally, I explore variation within genera where a significant number of counts have been made. Given the distributions of counts within genera there is evidence for both agmatoploid and polyploid chromosome number changes.

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Chromosome Numbers and Basic Chromosome Numbers in Monocotyledonous Genera of the Western Himalayas (India)

Kaur¹,

Mubarik²,

Kumari³

et al. 2015

Acta Biologica Cracoviensia S. Botanica

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Worldwide chromosome number information has been compiled from the literature for monocotyledonous genera whose members have been cytologically studied in the last three years from Kangra District (Himachal Pradesh) and Kashmir (Jammu & Kashmir) in the Western Himalayas, comprising 143 species of 86 genera in 12 families, many in the family Poaceae. Chromosome number information from the literature is supplemented with new and varied reports for 54 species/56 taxa from the present study. Overall, the chromosome numbers range from 2n=10 to 2n=120. Some species in all genera show a large number of cytotypes, clearly highlighting the role of inter- and intraspecific genetic diversity as well as polyploidy and dysploidy. The basic chromosome numbers in all 86 genera are reconsidered. Monobasic genera are more common in Poaceae, and polyba-sic genera are more common in the other 11 families. Polyploidy in the different genera ranges from 3x to 40x, and is quite high in certain genera (18x in Avena, Bothriochloa, Isachne, Helictotrichon and Panicum; 19x in Saccharum; 24x in Tradescantia; 28x in Eleocharis; 32x in Cyperus; 36x in Andropogon; 38x in Poa; 40x in Dioscorea). An updated checklist of chromosome number variability in these genera is given for India and world-wide.

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Cytological studies in some South Indian species of Carex.

Cited by 3 publications

References 19 publications

The Evolution of Chromosome Arrangements in Carex (Cyperaceae)

The Evolution of Chromosome Arrangements in Carex (Cyperaceae)

A Synopsis of Chromosome Number Variation in the Cyperaceae

Chromosome Numbers and Basic Chromosome Numbers in Monocotyledonous Genera of the Western Himalayas (India)

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