New chromosome numbers and remarks on theAchillea millefolium polyploid complex in North America

1973 ◽  
Vol 122 (3) ◽  
pp. 133-143 ◽  
Author(s):  
Friedrich Ehrendorfer
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Polyploid Complex

Chromosome numbers in Antennaria (Asteraceae:Inuleae) from western North America

1986 ◽  
Vol 28 (3) ◽  
pp. 468-475 ◽  
Author(s):  
C. C. Chinnappa
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Entire Range ◽  
Western North America ◽  
Polyploid Complex ◽  
Polyploid Species ◽  
Ploidy Levels ◽  
Putative Hybrids

Chromosome numbers were determined for 26 taxa of Antennaria from western North America. These were found to include diploid and polyploid species and their putative hybrids. First counts are reported for A. stenophylla (2n = 28) and A. sedoides (2n = 56). Four polyploid complexes, the A. rosea, A. alpina, A. neodioeca, and A. parvifolia aggregates, were found to have sporophytic chromosomes numbers which included all ploidy levels from diploid (2n = 28) to decaploid (2n = 140). This represents the entire range of euploidy known to occur in the genus. Much of the variation that is encountered in the species of Antennaria is the result of extensive hybridization between diploid and polyploid populations comprised of sexual and partially apomictic individuals, respectively.Key words: Asteraceae, Antennaria, dioecy, agamospermy, polyploid complex.

scholarly journals Cytogenetics and Genome Size Evolution in Illicium L.

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 620-623
Author(s):  
Thomas G. Ranney ◽  
Connor F. Ryan ◽  
Lauren E. Deans ◽  
Nathan P. Lynch
Keyword(s):  
North America ◽  
Plant Breeding ◽  
Genome Size ◽  
Chromosome Numbers ◽  
Phylogenetic Analyses ◽  
Basal Angiosperm ◽  
Ploidy Levels ◽  
Genome Size Evolution ◽  
Size Evolution ◽  
Improvement Programs

Illicium is an ancient genus and member of the earliest diverging angiosperms known as the Amborellales, Nymphaeales, and Austrobaileyales (ANA) grade. These adaptable, broadleaf evergreen shrubs, including ≈40 species distributed throughout Asia and North America, are valued for diverse culinary, medicinal, and ornamental applications. The study of cytogenetics of Illicium can clarify various discrepancies and further elucidate chromosome numbers, ploidy, and chromosome and genome size evolution in this basal angiosperm lineage and provide basic information to guide plant breeding and improvement programs. The objectives of this study were to use flow cytometry and traditional cytology to determine chromosome numbers, ploidy levels, and relative genome sizes of cultivated Illicium. Of the 29 taxa sampled, including ≈11 species and one hybrid, 2C DNA contents ranged from 24.5 pg for Illicium lanceolatum to 27.9 pg for Illicium aff. majus. The genome sizes of Illicium species are considerably higher than other ANA grade lineages indicating that Illicium went through considerable genome expansion compared with sister lineages. The New World sect. Cymbostemon had a slightly lower mean 2C genome size of 25.1 pg compared with the Old World sect. Illicium at 25.9 pg, providing further support for recognizing these taxonomic sections. All taxa appeared to be diploid and 2n = 2x = 28, except for Illicium floridanum and Illicium mexicanum which were found to be 2n = 2x = 26, most likely resulting from dysploid reduction after divergence into North America. The base chromosome number of x = 14 for most Illicium species suggests that Illicium are ancient paleotetraploids that underwent a whole genome duplication derived from an ancestral base of x = 7. Information on cytogenetics, coupled with phylogenetic analyses, identifies some limitations, but also considerable potential for the development of plant breeding and improvement programs with this genus.

Chromosome numbers and sexual compatibility in North America of Rorippa sylvestris (Cruciferae)

1984 ◽  
Vol 62 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Gerald A. Mulligan ◽  
Derek B. Munro
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Field Observations ◽  
Sexual Compatibility ◽  
Intraspecific Crossing

Tetraploid (2n = 32), pentaploid (2n = 40), and hexaploid (2n = 48) plants of Rorippa sylvestris (L.) Besser (Cruciferae) and a natural pentaploid (2n = 40) interspecific hybrid, R. sylvestris × R. palustris (L.) Besser, are recorded for North America. These counts are compared with published information on European plants. Tetraploids are most common in Europe (68 vs. 20%), whereas hexaploids are most common in North America (65 vs. 29%). Although self-incompatible R. sylvestris rarely sets seed in nature, indicating that plants within most sites are genetically the same clone, intraspecific crossing data, chromosome information, and field observations indicate that North American R. sylvestris results from the vegetative introduction of many different genotypes.

Chromosome Numbers in Some Cacti of Western North America-VIII

Haseltonia ◽  
2009 ◽  
Vol 15 ◽  
pp. 117-134 ◽  
Author(s):  
Marc A Baker ◽  
Jon P Rebman ◽  
Bruce D Parfitt ◽  
Donald J Pinkava ◽  
Allan D Zimmerman
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Western North America

Cytoevolutionary Studies in the Genus Bulbine Wolf (Liliaceae) .II. The Australian Annual Taxa (Bulbine semibarbata s.1.)

1986 ◽  
Vol 34 (5) ◽  
pp. 505 ◽  
Author(s):  
EM Watson
Keyword(s):  
Species Richness ◽  
Chromosome Numbers ◽  
The Other ◽  
Root Tip ◽  
Polyploid Complex ◽  
Southwestern Australia ◽  
Australian Species ◽  
Eastern Australia ◽  
Karyotypic Diversity ◽  
Interpopulation Variation

A cytological survey, using root tip mitotic cells and supplemented by some crosses and pollen fertility studies, was carried out on plants of 55 populations of the Australian annual Bulbine sernibarbata s.1. (Liliaceae). There are 4x, 8x and 12.x populations.The 4x forms are almost completely confined to eastern Australia and comprise populations of two kinds: (1) 28-chromosome types, corresponding in morphology to B. alata Baijnath, which to date has had limited taxonomic acceptance; (2) 26-chromosome types with the morphology of B. sernibarbata s. str. The alata form occurs in arid, the sernibarbata in more mesic, areas. The eastern 8x populations are mainly 2n = 54 and are intermediate between the other two taxa in both range and morphology. This suggests an allopolyploid origin based on hybridisation between the alata and sernibarbata types. The western 8x populations are nearly all 2n = 52, with much interpopulation variation in karyotype and a mesic distribution similar to that of the eastern 26-chromosome types. The karyotypic diversity parallels the species richness of other genera in southwestern Australia and indicates that the complex may be older than the corresponding polyploid complex within the perennial B. bulbosa s.1. The 12x (2n =78) populations are confined to arid and transitional rainfall areas of Western Australia. The identification of a distinctive 28-chromosome karyotype for the alata group gives support to the recognition of B. alata Baijnath, and, by providing a logical euploid bridge between the chromosome numbers of the African (2n = 14) and Australian species, strengthens the arguments for treating the two groups as congeneric.

DNA content in Tradescantia

1985 ◽  
Vol 27 (6) ◽  
pp. 766-775 ◽  
Author(s):  
Arturo Martínez ◽  
Héctor D. Ginzo
Keyword(s):  
North America ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Life Forms ◽  
Chromosome Size ◽  
Polyploid Complex ◽  
Ploidy Levels ◽  
Vegetative Adaptation ◽  
The Relationship

There is a wide variation in the nuclear DNA content and chromosome size between the species belonging to the T. crassifolia and T. virginiana alliances (all the species but one are native to Central and North America). Also the DNA content per genome decreases when the ploidy level increases within the same specific polyploid complex with three ploidy levels (2x, 4x, and 6x). In contrast, no variation was found in the DNA content per genome between different ploidy levels in the T. fluminensis alliance (all the species are native to South America) where they range from 6x to 22x. Since all the species described here are perennials with various life forms, it was possible to analyze the relationship between the DNA content and their vegetative adaptation to the environment. The more specialized species (geophytes and hemicryptophytes) have a higher amount of DNA than the chamaephytes adapted to live in relatively more mesic regions. In the species living in Central and North America there is a positive correlation between the increase in DNA content and the latitude of their native regions.Key words: Tradescantia, DNA content, geographical distribution, life forms, polyploidy.

Chromosome Numbers in Some Cacti of Western North America-III

1977 ◽  
Vol 104 (2) ◽  
pp. 105 ◽  
Author(s):  
Donald J. Pinkava ◽  
Lyle A. McGill ◽  
Timothy Reeves
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Western North America

STUDIES ON SOLIDAGO L.: IV. THE CHROMOSOME NUMBERS OF CERTAIN TAXA OF THE GENUS SOLIDAGO

1959 ◽  
Vol 37 (2) ◽  
pp. 209-228 ◽  
Author(s):  
Jean R. Beaudry ◽  
Denise L. Chabot
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Geographical Distribution ◽  
Chromosome Numbers ◽  
Morphological Characters ◽  
Basic Number ◽  
Western North America

The authors report the chromosome numbers of 25 taxa of the genus Solidago which had not yet been studied from this standpoint, and review the literature. The chromosome numbers of 42 taxa have now been published. The basic number of the genus is nine. Thirty-three taxa are diploid (2n = 18), five are tetraploid (2n = 36), three are aggregate taxa containing both diploid and tetraploid cytodemes, and one is hexaploid (2n = 54). Polyploidy has thus contributed to the evolution of the genus Solidago but it seems that most of the species have differentiated gradually. S. decemflora DC. of western North America differs from S. nemoralis Ait. of the same continent by morphological characters, its geographical distribution, and its chromosome number, the first taxon being tetraploid and the second diploid; the two are thus good species and not only varieties of the same species. The S. rigida of authors is an aggregate made up of two entities which are distinguished not only by their morphology and geographical distribution but also by their chromosome numbers; the eastern one (S. rigida L.) is tetraploid, whereas the western one (S. parvirigida Beaudry) is diploid. The bog and marsh goldenrods, S. Purshii and S. uliginosa, also possess different chromosome numbers, the first being diploid and the second tetraploid.

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