scholarly journals Genome Size and Ploidy Levels of Cercis (Redbud) Species, Cultivars, and Botanical Varieties

HortScience ◽  
2016 ◽  
Vol 51 (4) ◽  
pp. 330-333 ◽  
Author(s):  
David J. Roberts ◽  
Dennis J. Werner
Keyword(s):  
Genome Size ◽  
Size Variation ◽  
Internal Standard ◽  
Close Relative ◽  
Genome Size Variation ◽  
Ploidy Levels ◽  
Wide Range ◽  
Average Size ◽  
Size Estimates ◽  
Botanical Varieties

Cercis is an ancient member of Fabaceae, often cultivated as an ornamental tree, and can be found in numerous regions around the world. Previous studies have reported Cercis canadensis as being diploid with 2n = 2x = 14. However, there have been no further investigations into ploidy and genome size variation among Cercis taxa. A study was conducted to evaluate the relative genome size and ploidy levels of numerous species, cultivars, and botanical varieties of Cercis, representing taxa found in North America, Asia, and the Middle East. In addition, the genome size of Bauhinia forficata, a close relative of Cercis, was also determined. Genome size estimates (2C values) were determined by calculating the mean fluorescence of stained nuclei via flow cytometry. Propidium iodide was used as the staining agent and Glycine max was used as an internal standard for each taxon analyzed. Genome size estimates for all Cercis sampled ranged from 0.70 to 0.81 pg with an average size of 0.75 pg. The genome size of B. forficata was found to be smaller than any other Bauhinia sp. currently on record, with an average size of 0.87 pg. This study confirmed an initial estimation of the genome size of Cercis chinensis and found that floral buds of Cercis proved to be an excellent source of plant tissue for obtaining intact nuclei. All species, botanical varieties, and cultivars of Cercis surveyed for this study had remarkably similar genome sizes despite their wide range of distribution. This information can facilitate a better understanding of phylogenetic relationships within Cercideae and Cercis specifically.

scholarly journals Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China

2021 ◽  
Vol 15 (2) ◽  
pp. 137-148
Author(s):  
Jiabao Li ◽  
Kailin Zhu ◽  
Qin Wang ◽  
Xin Chen
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Size Variation ◽  
Sensu Stricto ◽  
Chromosome Size ◽  
Chromosome Counting ◽  
Genome Size Variation ◽  
Ploidy Levels ◽  
First Time ◽  
Karyotype Symmetry

Eight taxa of Sorbus Linnaeus, 1753 sensu stricto (Rosaceae) from China have been studied karyologically through chromosome counting, chromosomal measurement and karyotype symmetry. Genome size was also estimated by flow cytometry. Six taxa, S. amabilis Cheng ex T.T.Yu et K.C.Kuan, 1963, S. hupehensis var. paucijuga (D.K. Zang et P.C. Huang, 1992) L.T. Lu, 2000, S. koehneana C.K. Schneider, 1906, S. pohuashanensis (Hance, 1875) Hedlund, 1901, S. scalaris Koehne, 1913 and S. wilsoniana C.K. Schneider, 1906 are diploids with 2n = 34, whereas two taxa, S. filipes Handel-Mazzetti,1933 and S. ovalis McAllister, 2005 are tetraploid with 2n = 68. In general, the chromosome size is mainly small, and karyotypes are symmetrical with predominance of metacentric chromosomes. Genome size variation of diploids and tetraploids is 1.401 pg –1.676 pg and 2.674 pg –2.684 pg, respectively. Chromosome numbers of S. amabilis and S. hupehensis var. paucijuga, and karyotype and genome size of eight taxa studied are reported for the first time. This study emphasised the reliability of flow cytometry in genome size determination to infer ploidy levels in Chinese native Sorbus species.

Genome size increases in recently diverged hornwort clades

Genome ◽  
2013 ◽  
Vol 56 (8) ◽  
pp. 431-435 ◽  
Author(s):  
Jillian D. Bainard ◽  
Juan Carlos Villarreal
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
Size Variation ◽  
Plant Genome ◽  
Ancestral Reconstruction ◽  
Genome Size Variation ◽  
Important Group ◽  
Content Variation ◽  
Dna Content Variation ◽  
Size Estimates

As our knowledge of plant genome size estimates continues to grow, one group has continually been neglected: the hornworts. Hornworts (Anthocerotophyta) have been traditionally grouped with liverworts and mosses because they share a haploid dominant life cycle; however, recent molecular studies place hornworts as the sister lineage to extant tracheophytes. Given the scarcity of information regarding the DNA content of hornworts, our objective was to estimate the 1C-value for a range of hornwort species within a phylogenetic context. Using flow cytometry, we estimated genome size for 36 samples representing 24 species. This accounts for roughly 10% of known hornwort species. Haploid genome sizes (1C-value) ranged from 160 Mbp or 0.16 pg (Leiosporoceros dussii) to 719 Mbp or 0.73 pg (Nothoceros endiviifolius). The average 1C-value was 261 ± 104 Mbp (0.27 ± 0.11 pg). Ancestral reconstruction of genome size on a hornwort phylogeny suggests a small ancestral genome size and revealed increases in genome size in the most recently divergent clades. Much more work is needed to understand DNA content variation in this phylogenetically important group, but this work has significantly increased our knowledge of genome size variation in hornworts.

Nuclear DNA content in Sinningia (Gesneriaceae); intraspecific genome size variation and genome characterization in S. speciosa

Genome ◽  
2010 ◽  
Vol 53 (12) ◽  
pp. 1066-1082 ◽  
Author(s):  
David Zaitlin ◽  
Andrew J. Pierce
Keyword(s):  
Genome Size ◽  
Nuclear Dna ◽  
Size Variation ◽  
Nuclear Genome ◽  
Nuclear Dna Content ◽  
Size Estimation ◽  
Cell Nuclei ◽  
Genome Size Variation ◽  
Genome Survey ◽  
Size Estimates

The Gesneriaceae (Lamiales) is a family of flowering plants comprising >3000 species of mainly tropical origin, the most familiar of which is the cultivated African violet ( Saintpaulia spp.). Species of Gesneriaceae are poorly represented in the lists of taxa sampled for genome size estimation; measurements are available for three species of Ramonda and one each of Haberlea , Saintpaulia, and Streptocarpus , all species of Old World origin. We report here nuclear genome size estimates for 10 species of Sinningia , a neotropical genus largely restricted to Brazil. Flow cytometry of leaf cell nuclei showed that holoploid genome size in Sinningia is very small (approximately two times the size of the Arabidopsis genome), and is small compared to the other six species of Gesneriaceae with genome size estimates. We also documented intraspecific genome size variation of 21%–26% within a group of wild Sinningia speciosa (Lodd.) Hiern collections. In addition, we analyzed 1210 genome survey sequences from S. speciosa to characterize basic features of the nuclear genome such as guanine–cytosine content, types of repetitive elements, numbers of protein-coding sequences, and sequences unique to S. speciosa. We included several other angiosperm species as genome size standards, one of which was the snapdragon ( Antirrhinum majus L.; Veronicaceae, Lamiales). Multiple measurements on three accessions indicated that the genome size of A. majus is ∼633 × 106 base pairs, which is approximately 40% of the previously published estimate.

scholarly journals Diversification of Aeonium Species Across Macaronesian Archipelagos: Correlations Between Genome-Size Variation and Their Conservation Status

2021 ◽  
Vol 9 ◽  
Author(s):  
Miguel Brilhante ◽  
Guilherme Roxo ◽  
Sílvia Catarino ◽  
Patrícia dos Santos ◽  
J. Alfredo Reyes-Betancort ◽  
...  
Keyword(s):  
Genome Size ◽  
Environmental Variables ◽  
Morphological Traits ◽  
Conservation Status ◽  
Size Variation ◽  
Ecological Niches ◽  
Conservation Priorities ◽  
Genome Size Variation ◽  
Wide Range ◽  
Macaronesian Islands

The rich endemic flora of the Macaronesian Islands places these oceanic archipelagos among the top biodiversity hotspots worldwide. The radiations that have determined the evolution of many of these insular lineages resulted in a wealth of endemic species, many of which occur in a wide range of ecological niches, but show small distribution areas in each of them. Aeonium (Crassulaceae) is the most speciose lineage in the Canary Islands (ca. 40 taxa), and as such can be considered a good model system to understand the diversification dynamics of oceanic endemic floras. The present study aims to assess the genome size variation within Aeonium distribution, i.e., the Macaronesian archipelagos of Madeira, Canaries and Cabo Verde, and analyse it together with information on distribution (i.e., geography and conservation status), taxonomy (i.e., sections), morphological traits (i.e., growth-form), geological data (i.e., island's geological age), and environmental variables (i.e., altitude, annual mean temperature, and precipitation). Based on extensive fieldwork, a cytogeographic screening of 24 Aeonium species was performed. The conservation status of these species was assessed based on IUCN criteria. 61% of the taxa were found to be threatened (4% Endangered and 57% Vulnerable). For the first time, the genome size of a comprehensive sample of Aeonium across the Macaronesian archipelagos was estimated, and considerable differences in Cx-values were found, ranging from 0.984 pg (A. dodrantale) to 2.768 pg (A. gorgoneum). An overall positive correlation between genome size and conservation status was found, with the more endangered species having the larger genomes on average. However, only slight relationships were found between genome size, morphological traits, and environmental variables. These results underscore the importance of characterizing the cytogenomic diversity and conservation status of endemic plants found in Macaronesian Islands, providing, therefore, new data to establish conservation priorities.

Genome-size evolution in fishes

2004 ◽  
Vol 61 (9) ◽  
pp. 1636-1646 ◽  
Author(s):  
David C Hardie ◽  
Paul DN Hebert
Keyword(s):  
Genome Size ◽  
Size Variation ◽  
Evolutionary Significance ◽  
Genome Size Variation ◽  
Genome Size Evolution ◽  
Size Evolution ◽  
Size Diversity ◽  
Cartilaginous Fishes ◽  
Egg Diameter ◽  
Size Estimates

Fishes possess both the largest and smallest vertebrate genomes, but the evolutionary significance of this variation is unresolved. The present study provides new genome-size estimates for more than 500 species, with a focus on the cartilaginous and ray-finned fishes. These results confirm that genomes are smaller in ray-finned than in cartilaginous fishes, with the exception of polyploids, which account for much genome-size variation in both groups. Genome-size diversity in ray-finned fishes is not related to metabolic rate, but is positively correlated with egg diameter, suggesting linkages to the evolution of parental care. Freshwater and other eurybiotic fishes have larger genomes than their marine and stenobiotic counterparts. Although genome-size diversity among the fishes appears less clearly linked to any single biological correlate than in the birds, mammals, or amphibians, this study highlights several particularly variable taxa that are suitable for further study.

scholarly journals Polyploidy and genome size variation in Phlox nana (Polemoniaceae) from the Pecos plains of New Mexico and the Davis Mountains of West Texas

2017 ◽  
Vol 11 (2) ◽  
pp. 351-362
Author(s):  
Jamie Ladner ◽  
Mark H. Mayfield ◽  
L. Alan Prather ◽  
Carolyn J. Ferguson
Keyword(s):  
New Mexico ◽  
Genome Size ◽  
Size Variation ◽  
Chromosome Counts ◽  
Genome Size Variation ◽  
Ploidy Levels ◽  
West Texas ◽  
Popula Tions ◽  
Davis Mountains ◽  
Parapatric Distribution

Polyploidy is conspicuous in the genus Phlox, and some species exhibit variation in ploidy levels, or cytotypic variation. Diploid, tetraploid and hexaploid popula-tions of P. nana occur across parts of the species distribution in the southwestern United States and northern Mexico. A recent study highlighted two areas for which ploidy level inferences were challenging: a population on the Pecos Plains of New Mexico (“Caprock”) and the Davis Mountains region of West Texas. Plants in these areas were sampled and chromosome counts and flow cytometry methods were used to assess ploidy levels and genome sizes. Homoploid variation in ge-nome size was unambiguously documented: the genome size of tetraploid plants from the Davis Mountains was significantly larger than that of plants from Caprock. The general condition of larger genome sizes for plants in the Davis Mountains explains previous difficulty in determining ploidy levels within the region. Most plants at the Caprock population appeared to be tetraploid (2n=28), but chromosome counts revealed variants, including some putative pentaploids. Within the Davis Mountains region, both diploid (2n=14) and tetraploid (2n=28) cytotypes were documented, with a parapatric distribution. Overall, this study clarifies patterns of cytotypic diversity in P. nana, highlights an example of infraspecific, homoploid genome size variation, and contributes to a framework for ongoing evolutionary investigation in this study system.

scholarly journals Genome size variation in Deschampsia cespitosa sensu lato (Poaceae) in Eurasia

2022 ◽  
Vol 308 (1) ◽  
Author(s):  
Josef Greimler ◽  
Eva M. Temsch ◽  
Zhiqing Xue ◽  
Hanna Weiss-Schneeweiss ◽  
Polina Volkova ◽  
...  
Keyword(s):  
Genome Size ◽  
Size Variation ◽  
Genome Size Variation ◽  
Geographic Scale ◽  
Reproduction Mode ◽  
Ploidy Levels ◽  
Deschampsia Cespitosa ◽  
Flow Cytometric ◽  
Significant Difference ◽  
Disturbed Habitats

AbstractThe grass Deschampsia cespitosa is a variable taxon out of which many varieties, subspecies and endemic species have been separated. In this paper, the variation in genome size (GS) and ploidy of this grass including several of its subspecies and two related species in Eurasia was investigated by flow cytometric (FCM) measurements. GS and ploidy data were also related to specific environments and reproduction mode. Ploidy levels found by FCM were confirmed by chromosome counts of diploid (2n = 28) and tetraploid (2n = 52) samples. Seminiferous (seed bearing) D. cespitosa was mainly diploid (GS between 3.754 and 5.438 pg/1C). GS variation in diploids showed a geographic pattern with a significant difference (H = 41,441, P < 0.001) between European (median = 4.377 pg) and Asian (median = 4.881 pg) accessions. Genome size (1C) in tetraploids ranged from 7.9426 to 9.0399 pg. Tetraploid seminiferous D. cespitosa was found mostly in disturbed habitats in western and southern Europe, while tetraploids in Asia were registered in wet Arctic habitats. Genome size (1C between 8.3278 and 8.8603 pg) of the pseudoviviparous plants (spikelets produce plantlets asexually) of wet habitats in central and northern Europe indicated tetraploidy. A putative triploid (GS 6.6817 pg) was detected in Iceland. Summing up, we found a high variation in GS on the geographic scale with significant regional differences in diploid D. cespitosa. Among the tetraploids, the asexually reproducing plants were bound to specific habitats, while the seminiferous plants showed a habitat preference similar to the diploids.

scholarly journals Genome Size Variation in Elms (Ulmus spp.) and Related Genera

HortScience ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 547-553 ◽  
Author(s):  
Alan T. Whittemore ◽  
Zheng-Lian Xia
Keyword(s):  
Genome Size ◽  
North American ◽  
Size Variation ◽  
North American Species ◽  
Dutch Elm Disease ◽  
Close Relative ◽  
Genome Size Variation ◽  
Ulmus Americana ◽  
The North ◽  
Disease Resistant

Elms (Ulmus spp.) are iconic street and landscape trees, but their use is currently limited by susceptibility to disease, especially Dutch elm disease (DED). Improved access to disease-resistant germplasm will be of great benefit for ongoing breeding and selection programs, but these programs have been limited historically by uncertain relationships among Ulmus species, especially the North American species and their putative Old World relatives. Estimates of genome size from 28 species representing both subgenera of Ulmus (subg. Ulmus and subg. Oreoptelea) and six species in the related small genera Zelkova, Hemiptelea, and Planera were estimated using flow cytometry. Genome-size estimates were calibrated using seven elms with known chromosome counts. Results strongly supported the subgeneric classification of Wiegrefe et al. Monoploid genome size was found to be quite constant within the subgenera of Ulmus they recognized and within the small genera, and polyploidy is uncommon in these plants. However, there are consistent differences in genome size between the subgenera of Ulmus and between them and the smaller genera, and these differences can be used to place species in their proper taxon, knowledge which can be useful in identifying disease-resistant germplasm that may be compatible with Ulmus americana and other North American taxa. Two Asian species that have sometimes been considered to be related to North American species now placed in subg. Oreoptelea were tested. The Himalayan Ulmus villosa has a much smaller genome than either of the subgenera, indicating that its relationship with other elms is rather remote. It may be a source of novel genes in Ulmus, but our results indicate it is not close to U. americana or other New World species. In contrast, results from the rare Chinese species Ulmus elongata support its placement in subg. Oreoptelea. It is the only close relative of the North American elms that is native to Asia, where DED is believed to have originated, and its response to DED infection should be evaluated.

scholarly journals Nuclear genome size variation in the allopolyploid Onosma arenaria – O. pseudoarenaria species group: methodological issues and revised data

Botany ◽  
2018 ◽  
Vol 96 (6) ◽  
pp. 397-410 ◽  
Author(s):  
V. Kolarčik ◽  
V. Kocová ◽  
D. Caković ◽  
T. Kačmárová ◽  
J. Piovár ◽  
...  
Keyword(s):  
Genome Size ◽  
Size Variation ◽  
Nuclear Genome ◽  
Taxonomic Revision ◽  
Balkan Peninsula ◽  
Species Group ◽  
Genome Size Variation ◽  
Size Groups ◽  
Internal Standardization ◽  
Size Estimates

We used flow cytometry (FCM) to investigate genome size variation in two polymorphic allopolyploids, Onosma arenaria Waldst. and Kit. and O. pseudoarenaria Schur, in Central Europe and the Balkan Peninsula. An intercalating DNA stain, propidium iodide (PI), and internal standardization were used. Our data showed that cytosolic compounds may be present in FCM samples and could inhibit, or more frequently promote, PI intercalation. In the absence of PI intercalation interference, leaf-based genome size estimates were observed to be lower than seed-based ones in O. pseudoarenaria, whereas no difference was recorded in O. arenaria. In incubation tests, genome size values frequently increase after a longer staining period. For final genome size measurements, we applied the FCM protocol based on seed material using a ∼150 min incubation period, and provide evidence of mean genome size variation among populations of both species. Two and four natural genome size groups were revealed in O. arenaria and O. pseudoarenaria respectively. Group mean genome sizes varied considerably in both O. arenaria (5.36–5.76 pg) and O. pseudoarenaria (5.98–6.58 pg). This extensive genome size variation is attributed to unexplored taxonomic heterogenity in both taxa. Future taxonomic revision of the group may be supported with genome size measurements obtained using an appropriately standardized methodology.

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