Polyploid polymorphism in Andropogon gerardii

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 374-379 ◽  
Author(s):  
K. H. Keeler ◽  
B. Kwankin ◽  
P. W. Barnes ◽  
D. W. Galbraith

The relationship between nuclear DNA content and chromosome number was investigated in Andropogon gerardii. The distribution of cytotypes in a natural population of this grass was also examined. Nuclear DNA content was determined using flow cytometry rather than the traditional method of Feulgen microphotometry. Our results demonstrate the increased accuracy and speed of this new method in the detection and study of polyploidy. Nuclear DNA content is strongly correlated to chromosome number in Andropogon gerardii (r = 0.971, P <0.01). The natural population of this grass was found to consist of plants with 2N = 60 chromosomes (hexaploid cytotype) and 2N = 80 chromosomes (octoploid cytotype), in equal proportions. Intermediate cytotypes were lacking in the natural population, although three progeny plants grown in the greenhouse from wild-collected seed show intermediate values of nuclear DNA content and have 2N = 70 chromosomes. The two coexisting cytotypes are intermingled and show no difference in microhabitats. The absence of septaploids in the natural population suggests that the two cytotypes are probably reproductively isolated. Key words: polyploidy, DNA contents, flow cytometry, polymorphism.

1987 ◽  
Vol 8 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Jelle W.F. Reumer ◽  
Charles-H. Thiébaud

AbstractThe relationship is studied between the volume of osteocyte lacunae and the nuclear DNA content and level of ploidy in the genus Xenopus. The lacunae volume and the DNA content appear strongly correlated. The possible use of this relationship in the study of the evolution of the genus is discussed.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
B. J. M. Zonneveld

Genome size (C-value) was applied anew to investigate the relationships within the genus Hepatica (Ranunculaceae). More than 50 samples representing all species (except H. falconeri), from wild and cultivated material, were investigated. Species of Hepatica turn out to be diploid (), tetraploid ( ), and a possible pentaploid. The somatic nuclear DNA contents (2C-value), as measured by flow cytometry with propidium iodide, were shown to range from 33 to 80 pg. The Asiatic and American species, often considered subspecies of H. nobilis, could be clearly distinguished from European H. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies of H. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier for Hepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.


Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1950
Author(s):  
Guadalupe Palomino ◽  
Javier Martínez-Ramón ◽  
Verónica Cepeda-Cornejo ◽  
Miriam Ladd-Otero ◽  
Patricia Romero ◽  
...  

Echeveria is a polyploid genus with a wide diversity of species and morphologies. The number of species registered for Echeveria is approximately 170; many of them are native to Mexico. This genus is of special interest in cytogenetic research because it has a variety of chromosome numbers and ploidy levels. Additionally, there are no studies concerning nuclear DNA content and the extent of endopolyploidy. This work aims to investigate the cytogenetic characteristics of 23 species of Echeveria collected in 9 states of Mexico, analyzing 2n chromosome numbers, ploidy level, nuclear DNA content, and endopolyploidy levels. Chromosome numbers were obtained from root tips. DNA content was obtained from the leaf parenchyma, which was processed according to the two-step protocol with Otto solutions and propidium iodide as fluorochrome, and then analyzed by flow cytometry. From the 23 species of Echeveria analyzed, 16 species lacked previous reports of 2n chromosome numbers. The 2n chromosome numbers found and analyzed in this research for Echeveria species ranged from 24 to 270. The range of 2C nuclear DNA amounts ranged from 1.26 pg in E. catorce to 7.70 pg in E. roseiflora, while the 1C values were 616 Mbp and 753 Mbp, respectively, for the same species. However, differences in the level of endopolyploidy nuclei were found, corresponding to 4 endocycles (8C, 16C, 32C and 64C) in E. olivacea, E. catorce, E. juarezensis and E. perezcalixii. In contrast, E. longiflora presented 3 endocycles (8C, 16C and 32C) and E. roseiflora presented 2 endocycles (8C and 16C). It has been suggested that polyploidization and diploidization processes, together with the presence of endopolyploidy, allowed Echeveria species to adapt and colonize new adverse environments.


2014 ◽  
Vol 86 (4) ◽  
pp. 1849-1862 ◽  
Author(s):  
ANDREI C.P. NUNES ◽  
WELLINGTON R. CLARINDO

In Bromeliaceae, cytogenetic and flow cytometry analyses have been performed to clarify systematic and evolutionary aspects. Karyotyping approaches have shown the relatively high chromosome number, similar morphology and small size of the chromosomes. These facts have prevented a correct chromosome counting and characterization. Authors have established a basic chromosome number of x = 25 for Bromeliaceae. Recently, one karyomorphological analysis revealed that x = 25 is no longer the basic chromosome number, whose genome may have a polyploid origin. Besides cytogenetic characterization, the 2C DNA content of bromeliads has been measured. Nuclear DNA content has varied from 2C = 0.60 to 2C = 3.34 picograms. Thus, in relation to most angiosperms, the 2C DNA content of Bromeliaceae species as well as their chromosome size can be considered relatively small. In spite of some advances, cytogenetic and flow cytometry data are extremely scarce in this group. In this context, this review reports the state of the art in karyotype characterization and nuclear DNA content measurement in Bromeliaceae, emphasizing the main problems and suggesting prospective solutions and ideas for future research.


1994 ◽  
Vol 119 (6) ◽  
pp. 1312-1316 ◽  
Author(s):  
W. Vance Baird ◽  
Agnes S. Estager ◽  
John K. Wells

Using laser flow cytometry, nuclear DNA amounts were estimated for 12 Prunus species, representing three subgenera [Prunophora (Prunus), Amygdalus, and Cerasus (Lithocerasus)], two interspecific hybrids, four cultivars, and a synthetic polyploid series of peach consisting of haploids, diploids, triploids, and tetraploids (periclinal cytochimeras). Peach nuclear DNA content ranged from 0.30 pg for the haploid nuclei to 1.23 pg for the tetraploid nuclei. The diploid genome of peach is relatively small and was estimated to be 0.60±0.03 pg (or 5.8×108 nucleotide base pairs). The polyploid series represented the expected arithmetic progression, as genome size positively correlated with ploidy level (i.e., DNA content was proportional to chromosome number). The DNA content for the 12 diploid species and two interspecific diploid hybrids ranged from 0.57 to 0.79 pg. Genome size estimates were verified independently by Southern blot analysis, using restriction fragment length polymorphism clones as gene-copy equivalents. Thus, a relatively small and stable nuclear genome typifies the Prunus species investigated, consistent with their low, basic chromosome number (× = 8).


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 514D-514
Author(s):  
Rengong Meng ◽  
Chad E. Finn ◽  
Robert P. Doss

Knowledge of the chromosome number in Rubus would be valuable when planning crosses and identifying plants, etc., however, preparation of tissue for microscopic evaluation and chromosome counting is difficult and time-consuming. Flow cytometry offers a more-efficient approach to this task. DNA flow cytometry was used to determine the nuclear DNA content in 22 Rubus genotypes. The genotypes represented a range of reported chromosome numbers from 2x to 12x. Six of the genotypes were representatives of Rubus ursinus, which is reported to have both 8x and 12x forms. Samples of nuclei were prepared from leaf discs of newly emerged and mature leaves following published protocols with some modifications. The DNA content was estimated by comparison of the fluorescence of Rubus nuclei with an internal DNA standard. There was an increase in nuclear DNA content concurrent with the increase in chromosome number. In these studies DNA flow cytometry could differentiate genotypes that differed by 2x, such as 6x and 8x, but could not reliably distinguish genotypes that differed by 1x, such as 7x vs. 8x or 6x. Aneuploids cannot be differentiated at this time.


2001 ◽  
Vol 126 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Sandy Lin ◽  
Hsiao-Ching Lee ◽  
Wen-Huei Chen ◽  
Chi-Chang Chen ◽  
Yen-Yu Kao ◽  
...  

Nuclear DNA contents were estimated by flow cytometry in 18 Phalaenopsis Blume species and Doritis pulcherrima Lindl. DNA amounts differed 6.07-fold, from 2.74 pg/diploid nuclear DNA content (2C) in P. sanderiana Rchb.f. to 16.61 pg/2C in P. parishii Rchb.f. Nuclear DNA contents of P. aphrodite Rchb.f. clones, W01-38 (2n = 2x = 38), W01-41 (2n = 3x = 57), and W01-22 (2n = 4x = 76), displayed a linear relationship with their chromosome numbers, indicating the accuracy of flow cytometry. Our results also suggest that the 2C-values of the Phalaenopsis sp. correlate with their chromosome sizes. The comparative analyses of DNA contents may provide information to molecular geneticists and systematists for genome analysis in Phalaenopsis. Endoreduplication was found in various tissues of P. equestris at different levels. The highest degree of endoreduplication in P. equestris was detected in leaves.


Author(s):  
Terrence R. Tiersch ◽  
Robert W. Chandler ◽  
Klaus D. Kallman ◽  
Stephen S. Wachtel

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