Genome Sizes and Ploidy Levels in the Genus Kalmia

Kalmia is a highly ornamental genus of shrubs native to North America and Cuba and grown as a valuable nursery crop throughout much of the temperate world. Although most species of Kalmia have previously been found to be diploid with 2n = 2x = 24, one species, Kalmia polifolia, has been found to be tetraploid. However, sampling within the genus has been limited, and information on the ploidy levels of specific cultivars is lacking. The objective of this study was to determine the relative genome sizes and ploidy levels of species, hybrids, and cultivars of Kalmia. Flow cytometry was used to determine the relative genome sizes of 67 accessions representing species, interspecific hybrids, cultivars, and chemically induced polyploids. Traditional cytology was used to calibrate genome sizes with ploidy levels. Results showed that relative genome sizes were conserved with 1Cx values ranging from 0.57 pg for Kalmia carolina to 0.70 pg for Kalmia latifolia. Most species of Kalmia were diploid including K. buxifolia (Leiophyllum buxifolium), K. carolina, K. cuneata, K. hirsuta, K. latifolia, and K. microphylla. Although plants of K. carolina (Kalmia angustifolia var. carolina) were uniformly diploid, the closely related, but more northerly distributed, K. angustifolia was primarily tetraploid, providing additional justification for treating these as separate species. An unusual triploid of K. angustifolia f. candida was also documented. Kalmia polifolia included both tetraploid and potentially pentaploid individuals, indicating a ploidy series within this species. Kalmia latifolia cultivars also included one triploid, two cytochimeras, and two chemically induced tetraploids. Overall, polyploidy was more prevalent in Kalmia than previously reported and varied both within and among species. This broader survey of relative genome sizes and ploidy levels in Kalmia provides valuable information for plant breeders and new insights into the systematics and cytogenetics of the genus.

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Ploidy Levels and Relative Genome Sizes of Species, Hybrids, and Cultivars of Dogwood (Cornus spp.)

HortScience ◽

10.21273/hortsci.48.7.825 ◽

2013 ◽

Vol 48 (7) ◽

pp. 825-830 ◽

Cited By ~ 6

Author(s):

Kimberly Shearer ◽

Thomas G. Ranney

Keyword(s):

Interspecific Hybrids ◽

Interspecific Crosses ◽

Root Cells ◽

Ploidy Levels ◽

Cornelian Cherry ◽

Landscape Plants ◽

The World ◽

Considerable Work ◽

Hybrid Cultivar ◽

Species Hybrids

Dogwoods (Cornus spp.) are valuable nursery crops grown as landscape plants throughout much of the world. Although there has been considerable work on breeding and selecting dogwoods, there is little information available on genome sizes (DNA content) and ploidy levels within the genus, particularly for specific clones and cultivars. Our objective was to conduct a survey of relative genome sizes and ploidy levels of dogwood taxa representative of the big-bracted, cornelian cherry, and dwarf dogwood clades. Flow cytometry was used to determine relative genome sizes and ploidy levels of 94 accessions of various species, hybrids, and cultivars. Traditional cytology was performed on root cells of representative taxa to calibrate genome sizes with ploidy level. All dogwood accessions tested were diploid with the exception of C. canadensis that was tetraploid and the hybrid cultivar C. KN30-8 that was triploid. Relative genome sizes varied by clade, subgenus, and species with 1Cx values ranging from 1.07 pg for C. canadensis to 5.08 pg for C. eydeana. Relative genome sizes were also valuable for confirming hybridity of interspecific crosses in cases in which parents varied substantially in relative genome size and hybrids were intermediate. A broad range of interspecific hybrids was documented including C. capitata × florida, C. capitata × kousa, C. elliptica × florida, C. hongkongensis × florida, C. kousa × elliptica, and C. kousa × florida. These results provide further insights into the cytogenetics, reproductive biology, crossability, and relative genome sizes of dogwoods.

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Characterizing polyploidy in Arabidopsis lyrata using chromosome counts and flow cytometry

Canadian Journal of Botany ◽

10.1139/b03-134 ◽

2004 ◽

Vol 82 (2) ◽

pp. 185-197 ◽

Cited By ~ 49

Author(s):

Sara Dart ◽

Paul Kron ◽

Barbara K Mable

Keyword(s):

Flow Cytometry ◽

North America ◽

Dna Content ◽

Geographic Range ◽

Chromosome Counts ◽

Dynamic Nature ◽

Ploidy Levels ◽

Arabidopsis Lyrata ◽

Genomic Changes ◽

European Populations

Protocols were developed for both chromosome counts and flow cytometry to assess ploidy level and DNA content for populations of Arabidopsis lyrata L. sampled from Europe (Arabidopsis lyrata subsp. petraea), North America (Arabidopsis lyrata subsp. lyrata), and Japan (Arabidopsis lyrata subsp. kawasakiana). Ploidy variation within this species is not clear, with previous studies having documented both diploid and tetraploid populations. Chromosome counts in this study confirmed ploidy expectations for all populations examined. Individuals from Iceland and North America were diploid (2n = 2x = 16), whereas those from Japanese and Austrian populations were tetraploid (2n = 4x = 32). Flow cytometry was also used successfully to distinguish between ploidy levels, but the need to calibrate DNA content measures with chromosome counts was demonstrated by a deviation from the expected 2:1 ratio between tetraploid and diploid values among European populations (A. lyrata subsp. petraea). This deviation might be explained by a hybrid (allopolyploid) origin or by genomic changes following polyploidization, emphasizing the dynamic nature of polyploid genomes. Variation in DNA content among families was found only for North American populations, but these individuals were sampled from a broader geographic range than those from other regions.Key words: cytogenetics, flow cytometry, polyploidy, Arabidopsis lyrata, genome size, chromosome counts.

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Two ploidy levels of genetically delimited groups of the Calypogeia fissa complex (Jungermanniopsida, Calypogeiaceae)

Biodiversity Research and Conservation ◽

10.1515/biorc-2015-0022 ◽

2015 ◽

Vol 39 (1) ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Katarzyna Buczkowska ◽

Bartosz Hornik ◽

Magdalena Czołpińska

Keyword(s):

Flow Cytometry ◽

Molecular Markers ◽

North America ◽

Ploidy Level ◽

European Part ◽

Isozyme Pattern ◽

Ploidy Levels

Abstract Calypogeia fissa is a suboceanic-mediterrean and amphiatlantic species, which comprises two subspecies: C. fissa subsp. fissa occurring in Europe and C. fissa subsp. neogea Schust. known from North America. Recently, within the European part of distribution, three groups (PS, PB and G) were distinguished with the aid of genetic and molecular markers. The flow cytometry results revealed that two of the detected groups of the European C. fissa, which are frequent in Poland (PS and PB), differ in ploidy level: the PS group is haploid, whereas the PB group is diploid. Isozyme pattern at two loci may suggest an allopolyploid origin of the diploid PB group.

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Icelandic Birch Polyploids—The Case of a Perfect Fit in Genome Size

Journal of Botany ◽

10.1155/2010/347254 ◽

2010 ◽

Vol 2010 ◽

pp. 1-9 ◽

Cited By ~ 13

Author(s):

K. Anamthawat-Jónsson ◽

Æ. Th. Thórsson ◽

E. M. Temsch ◽

J. Greilhuber

Keyword(s):

Flow Cytometry ◽

Genome Size ◽

Interspecific Hybrids ◽

Introgressive Hybridization ◽

Frequent Occurrence ◽

Ploidy Levels ◽

Betula Nana ◽

Dwarf Birch ◽

Spring Leaf

Two birch species coexist in Iceland, dwarf birch Betula nana and tree birch B. pubescens. Both species are variable morphologically, which has been shown to be due to introgressive hybridization via interspecific hybrids. The aim of this study was to examine if the introgression could be related to genome size. We characterized 42 plants from Bifröst woodland morphologically and cytogenetically. The population consisted of diploid B. nana (38%), tetraploid B. pubescens (55%), and triploid hybrids (7%). Genome size was measured from 12 plants, using Feulgen DNA image densitometry (FDM) on spring leaf buds and flow cytometry (FCM) with dormant winter twigs. The use of winter twigs for FCM is novel. The average 1C-values for diploid, triploid, and tetraploid plants were 448, 666, and 882 Mbp, respectively. Monoploid genome sizes were found to be statistically constant among ploidy levels. This stability is in contrast to the different taxonomic positions of the di- and tetraploids and also contrasts with the frequent occurrence of genome downsizing in polyploids.

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Flow Cytometry-Based Determination of Ploidy from Dried Leaf Specimens in Genomically Complex Collections of the Tropical Forage Grass Urochloa s. l.

Genes ◽

10.3390/genes12070957 ◽

2021 ◽

Vol 12 (7) ◽

pp. 957

Author(s):

Paulina Tomaszewska ◽

Till K. Pellny ◽

Luis M. Hernández ◽

Rowan A. C. Mitchell ◽

Valheria Castiblanco ◽

...

Keyword(s):

Flow Cytometry ◽

Germplasm Collection ◽

Forage Grass ◽

Breeding Programs ◽

Robust Identification ◽

Ploidy Levels ◽

Sustainable Improvement ◽

Tropical Forage ◽

Relative Differences

Urochloa (including Brachiaria, Megathyrus and some Panicum) tropical grasses are native to Africa and are now, after selection and breeding, planted worldwide, particularly in South America, as important forages with huge potential for further sustainable improvement and conservation of grasslands. We aimed to develop an optimized approach to determine ploidy of germplasm collection of this tropical forage grass group using dried leaf material, including approaches to collect, dry and preserve plant samples for flow cytometry analysis. Our methods enable robust identification of ploidy levels (coefficient of variation of G0/G1 peaks, CV, typically <5%). Ploidy of some 348 forage grass accessions (ploidy range from 2x to 9x), from international genetic resource collections, showing variation in basic chromosome numbers and reproduction modes (apomixis and sexual), were determined using our defined standard protocol. Two major Urochloa agamic complexes are used in the current breeding programs at CIAT and EMBRAPA: the ’brizantha’ and ’humidicola’ agamic complexes are variable, with multiple ploidy levels. Some U. brizantha accessions have odd level of ploidy (5x), and the relative differences in fluorescence values of the peak positions between adjacent cytotypes is reduced, thus more precise examination of this species is required. Ploidy measurement of U. humidicola revealed aneuploidy.

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Analysis of ploidy level of Artemisia annua L. based on flow cytometry and confocal laser scanning microscopy

Bangladesh Journal of Botany ◽

10.3329/bjb.v50i1.52668 ◽

2021 ◽

Vol 50 (1) ◽

pp. 29-35

Author(s):

Shu-Gen Wei ◽

Ling-Yun Wan ◽

Ying Wei ◽

Li-Li He ◽

Jin-E Fu ◽

...

Keyword(s):

Flow Cytometry ◽

Confocal Laser Scanning Microscopy ◽

Laser Scanning ◽

Artemisia Annua ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Scanning Microscopy ◽

Confocal Laser ◽

Ploidy Levels ◽

Artemisia Annua L

Eighty nine Artemisia samples treated with different concentrations of colchicine were used as breeding samples, with diploid Artemisia as the control. The ploidy levels of samples were determined by flow cytometry and confocal laser scanning microscopy (CLSM). An analysis of the flow cytometry results identified three suspected tetraploid plants and seven suspected triploid plants. The results of this study may be useful for breeding new Artemisia lines.

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Ploidy Levels of Hardy Actinidia Accessions in the U.S. Determined by Flow Cytometry

HortScience ◽

10.21273/hortsci.32.3.439d ◽

1997 ◽

Vol 32 (3) ◽

pp. 439D-439 ◽

Cited By ~ 2

Author(s):

Mary Ann Start ◽

James Luby ◽

Robert Guthrie ◽

Debby Filler

Keyword(s):

Flow Cytometry ◽

Ploidy Level ◽

Interspecific Variation ◽

Root Tip ◽

Interspecific Crosses ◽

Ploidy Levels ◽

Haploid Chromosome Number ◽

Tip Cells ◽

Root Tip Cells ◽

The U.S

The hardy Actinidia species represent a source of genetic diversity for improving A. deliciosa (kiwifruit) as well as for creating new economically important cultivars through intra- and interspecific crosses. Attempts at breeding in Actinidia have been complicated by the existence of intraspecific as well as interspecific variation in ploidy. The haploid chromosome number in Actinidia is 29 and diploid (2n=2x=58), tetraploid (2n=4x=116), and hexaploid (2n=6x=174) levels have been identified. Because of the problems encountered when crossing parents differing in ploidy level, it is desirable to know the ploidy levels of plants to be used in breeding. We determined the ploidy levels of 61 Actinidia accessions currently available in the U.S., including primarily accessions of relatively winter-hardy species. The 61 accessions, representing eight species and three interspecific hybrids, were screened for ploidy using flow cytometry. Mitotic root tip cells from one plant from each putative ploidy level were examined microscopically to confirm the ploidy level derived from flow cytometry. There were 17 diploids, 40 tetraploids, and 4 hexaploids. Intraspecific variation was not found among accessions of the species arguta, callosa, deliciosa, kolomikta, melanandra, polygama, or purpurea. All kolomikta and polygama accessions were diploid. All arguta, callosa, melanandra, and purpurea accessions were tetraploid. Actinidia deliciosa was hexaploid. One chinensis accession was tetraploid. Two accessions (NGPR 0021.14 and 0021.3), acquired as chinensis, were hexaploid and may, in fact, be A. deliciosa based on their morphology. `Issai' (arguta × polygama) was hexaploid and `Ken's Red' and `Red Princess' (both melanandra × arguta) were tetraploid.

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Taxonomic affinities and paleogeography of Stromatomorpha californica Smith, a distinctive Upper Triassic reef-adapted demosponge

Journal of Paleontology ◽

10.1666/08-146.1 ◽

2009 ◽

Vol 83 (5) ◽

pp. 783-793 ◽

Cited By ~ 5

Author(s):

B. Senowbari-Daryan ◽

G. D. Stanley

Keyword(s):

North America ◽

Shallow Water ◽

Type Species ◽

Upper Triassic ◽

Northern Calcareous Alps ◽

Late Triassic ◽

Separate Species ◽

Northern Calcareous ◽

Siliceous Spicules ◽

Horizontal Layers

Stromatomorpha californica Smith is a massive, calcified, tropical to subtropical organism of the Late Triassic that produced small biostromes and contributed in building some reefs. It comes from the displaced terranes of Cordilleran North America (Eastern Klamath terrane, Alexander terrane, and Wrangellia). This shallow-water organism formed small laminar masses and sometimes patch reefs. It was first referred to the order Spongiomorphidae but was considered to be a coral. Other affinities that have been proposed include hydrozoan, stomatoporoid, sclerosponge, and chambered sponge. Part of the problem was diagenesis that resulted in dissolution of the siliceous spicules and/or replaced them with calcite. Well-preserved dendroclone spicules found during study of newly discovered specimens necessitate an assignment of Stromatomorpha californica to the demosponge order Orchocladina Rauff. Restudy of examples from the Northern Calcareous Alps extends the distribution of this species to the Tethys, where it was an important secondary framework builder in Upper Triassic (Norian-Rhaetian) reef complexes. Revisions of Stromatomorpha californica produce much wider pantropical distribution, mirroring paleogeographic patterns revealed for other tropical Triassic taxa. Review of Liassic material from the Jurassic of Morocco, previously assigned to Stromatomorpha californica Smith var. columnaris Le Maitre, cannot be sustained. Species previously included in Stromatomorpha are: S. stylifera Frech (type species, Rhaetian), S. actinostromoides Boiko (Norian), S. californica Smith (Norian), S. concescui Balters (Ladinian-Carnian), S. pamirica Boiko (Norian), S. rhaetica Kühn (Rhaetian), S. stromatoporoides Frech, and S. tenuiramosa Boiko (Norian). Stromatomorpha rhaetica Kühn described from the Rhaetian of Vorarlberg, Austria shows no major difference from S. californica. An example described as S. oncescui Balters from the Ladinian-Carnian of the Rarau Mountains, Romania, is very similar to S. californica in exhibiting similar spicule types. However, because of the greater distance between individual pillars, horizontal layers, and the older age, S. oncescui is retained as a separate species. The net-like and regular skeleton of Spongiomorpha sanpozanensis Yabe and Sugiyama, from the Upper Triassic of Sambosan (Tosa, Japan), suggests a closer alliance with Stromatomorpha, and this taxon possibly could be the same as S. californica.

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Cytogenetics and Genome Size Evolution in Illicium L.

HortScience ◽

10.21273/hortsci12922-18 ◽

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.

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