Karyotype characterization and nuclear DNA content measurement in Bromeliaceae: State of the art and future perspectives

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.

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Morphological and Cytological Characterization of Five Porterweed (Stachytarpheta) Selections

HortScience ◽

10.21273/hortsci15594-20 ◽

2021 ◽

pp. 1-6

Author(s):

Renjuan Qian ◽

S. Brooks Parrish ◽

Sandra B. Wilson ◽

Gary W. Knox ◽

Zhanao Deng

Keyword(s):

Chromosome Number ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Basic Chromosome Number ◽

Pollen Stainability ◽

Flower Number ◽

Ploidy Levels ◽

Basic Chromosome

Porterweed (Stachytarpheta spp.), a member of the verbena family, is frequently used in pollinator gardens to attract butterflies. This study was conducted to assess the morphological features, pollen stainability and morphology, nuclear DNA content, and chromosome number of five porterweed selections. Coral porterweed (S. mutabilis), ‘Naples Lilac’ porterweed (S. cayennensis × S. mutabilis ‘Violacea’), and nettleleaf porterweed (S. cayennensis) had the largest plant heights. Flower number was significantly higher in nettleleaf porterweed, jamaican porterweed (S. jamaicensis), and U*J3-2 porterweed (S. cayennensis × S. jamaicensis), with an average of 65–72 flowers per inflorescence. Internode length and flower width of jamaican porterweed had much lower values than the other selections. Coral porterweed recorded the lowest pollen stainability with only 10.6% stainability, but it had the largest relative pollen production. ‘Naples Lilac’ porterweed had the highest DNA content with an average of 3.79 pg/2C, like jamaican porterweed with 3.73 pg/2C. Ploidy levels varied between selections, and the basic chromosome number was x = 28. Coral, jamaican, and ‘Naples Lilac’ porterweed had 2n = 6x = 168 chromosomes, first reported in this genus. These results provide a guide and a new tool to distinguish native and non-native porterweed and may aid future breeding toward the production of noninvasive cultivars.

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Chromosome Number, Ploidy Level, and Nuclear DNA Content in 23 Species of Echeveria (Crassulaceae)

Genes ◽

10.3390/genes12121950 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1950

Author(s):

Guadalupe Palomino ◽

Javier Martínez-Ramón ◽

Verónica Cepeda-Cornejo ◽

Miriam Ladd-Otero ◽

Patricia Romero ◽

...

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Ploidy Level ◽

Dna Content ◽

Chromosome Numbers ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Root Tips ◽

Ploidy Levels ◽

Dna Amounts

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.

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Estimating Nuclear DNA Content in Peach and Related Diploid Species Using Laser Flow Cytometry and DNA Hybridization

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.119.6.1312 ◽

1994 ◽

Vol 119 (6) ◽

pp. 1312-1316 ◽

Cited By ~ 56

Author(s):

W. Vance Baird ◽

Agnes S. Estager ◽

John K. Wells

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Genome Size ◽

Dna Content ◽

Nuclear Dna ◽

Diploid Species ◽

Nuclear Genome ◽

Nuclear Dna Content ◽

Gene Copy ◽

Polyploid Series

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).

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Determination of DNA content and relative 2C genome sizes of some promising commercial varieties of sugarcane using flow cytometer

Current Botany ◽

10.19071/cb.2017.v8.3207 ◽

2017 ◽

Vol 8 ◽

Author(s):

A. Mondal S.K. Ghosal ◽

T. Pal Kalyan Kumar De

Keyword(s):

Flow Cytometry ◽

Genome Size ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Cane Yield ◽

Sugarcane Varieties ◽

Yield Information ◽

A Genome ◽

2C Dna Content

In the present study, 2C DNA content and the genome sizes (in picograms-pg and megabase pairs-Mbp respectively) of 19 promising commercial varieties of sugarcane, the derivatives of man-made interspecific hybrids between cultivated and wild species were analyzed using flow cytometry. In this work, 2C nuclear DNA content was determined. Knowing the 2C nuclear DNA content, the unknown chromosome numbers of the varieties could be predicted. Large differences (65 % variation) in DNA content (2C) of 19 varieties were detected, ranging, from 3.80 pg to 10.96 pg, which corresponds to a genome size ranging from 3724.00 Mbp to 10740.80 Mbp due to the variation of ploidy level and are considered the most complex genomes among crop plants. However, the relationship between chromosome number and genome size was highly significant (P < 0.001). In the present study, internode diameter, Sugar juice content and cane yield/ha are also positively correlated with DNA content. The estimated genome sizes would also yield information critical for sugarcane breeding and genome sequencing programs. Keywords: Genome size, Sugarcane varieties, Flow cytometry, DNA content.

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Polyploid polymorphism in Andropogon gerardii

Genome ◽

10.1139/g87-064 ◽

1987 ◽

Vol 29 (2) ◽

pp. 374-379 ◽

Cited By ~ 36

Author(s):

K. H. Keeler ◽

B. Kwankin ◽

P. W. Barnes ◽

D. W. Galbraith

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Natural Population ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Andropogon Gerardii ◽

Strongly Correlated ◽

Dna Contents ◽

The Relationship

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.

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Nuclear DNA content of commercially important Eucalyptus species and hybrids

Canadian Journal of Forest Research ◽

10.1139/x94-142 ◽

1994 ◽

Vol 24 (5) ◽

pp. 1074-1078 ◽

Cited By ~ 47

Author(s):

D. Grattapaglia ◽

H.D. Bradshaw Jr.

Keyword(s):

Flow Cytometry ◽

Dna Content ◽

Positional Cloning ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Eucalyptus Species ◽

Ploidy Levels ◽

2C Dna Content ◽

Haploid Genome Size ◽

Commercially Important

This paper reports the nuclear DNA content estimates obtained by flow cytometry for a group of twelve Eucalyptus species and five fast-growing hybrids that includes those most widely planted throughout the world. Estimates of nuclear (2C) DNA content for the species surveyed ranged from 0.77 pg/2C for Eucalyptuscitriodora Hook. (subgenus Corymbia) to 1.47 pg/2C for Eucalyptussaligna Smith (subgenus Symphyomyrtus). This range corresponds to a haploid genome size range of 370–700 megabase pairs. The average physical equivalent of a 1 cM distance could be as low as 200 kilobase pairs in Eucalyptus, an attractive feature for positional cloning efforts in woody plants. The closer the species were in phylogenetic relationship the more similar were their nuclear DNA content values. All the interspecific hybrids surveyed displayed a nuclear DNA content in the expected intermediate range between the respective parental species, with the exception of one originating from Rio Claro, Brazil, whose exact parentage is unknown. No evidence of polyploidy was observed in any of the hybrids. The flow cytometry procedure employed in this study is an efficient method for investigating ploidy levels of high yielding hybrids of Eucalyptus.

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Determination of Nuclear DNA Content and Ploidy Level in Rubus by Flow Cytometry

HortScience ◽

10.21273/hortsci.32.3.514d ◽

1997 ◽

Vol 32 (3) ◽

pp. 514D-514

Author(s):

Rengong Meng ◽

Chad E. Finn ◽

Robert P. Doss

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Dna Flow Cytometry ◽

Chromosome Counting ◽

Mature Leaves ◽

Microscopic Evaluation

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.

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