Evolution of genome size across some cultivated Allium species

Genome ◽  
2005 ◽  
Vol 48 (3) ◽  
pp. 511-520 ◽  
Author(s):  
A Ricroch ◽  
R Yockteng ◽  
S C Brown ◽  
S Nadot
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Internal Transcribed Spacer ◽  
Life Form ◽  
Nuclear Dna ◽  
Gc Content ◽  
Nuclear Dna Content ◽  
Dna Amount ◽  
Allium Species ◽  
Nuclear Dna Amount

Allium L. (Alliaceae), a genus of major economic importance, exhibits a great diversity in various morphological characters and particularly in life form, with bulbs and rhizomes. Allium species show variation in several cytogenetic characters such as basic chromosome number, ploidy level, and genome size. The purpose of the present investigation was to study the evolution of nuclear DNA amount, GC content, and life form. A phylogenetic approach was used on a sample of 30 Allium species, including major vegetable crops and their wild allies, belonging to the 3 major subgenera Allium, Amerallium, and Rhizirideum and 14 sections. A phylogeny was constructed using internal transcribed spacer (ITS) sequences of 43 accessions representing 30 species, and the nuclear DNA amount and the GC content of 24 Allium species were investigated by flow cytometry. For the first time, the nuclear DNA content of Allium cyaneum and Allium vavilovii was measured, and the GC content of 16 species was measured. We addressed the following questions: (i) Is the variation in nuclear DNA amount and GC content linked to the evolutionary history of these edible Allium species and their wild relatives? (ii) How did life form (rhizome or bulb) evolve in edible Allium? Our results revealed significant interspecific variation in the nuclear DNA amount as well as in the GC content. No correlation was found between the GC content and the nuclear DNA amount. The reconstruction of nuclear DNA amount on the phylogeny showed a tendency towards a decrease in genome size within the genus. The reconstruction of life form history showed that rhizomes evolved in the subgenus Rhizirideum from an ancestral bulbous life form and were subsequently lost at least twice independently in this subgenus.Key words: Allium, nuclear DNA amount, GC content, flow cytometry, internal transcribed spacer (ITS), phylogeny, life form.

Genome size and genome evolution in diploid Triticeae species

Genome ◽  
2007 ◽  
Vol 50 (11) ◽  
pp. 1029-1037 ◽  
Author(s):  
T. Eilam ◽  
Y. Anikster ◽  
E. Millet ◽  
J. Manisterski ◽  
O. Sagi-Assif ◽  
...  
Keyword(s):  
Genome Size ◽  
Intraspecific Variation ◽  
Dna Content ◽  
Nuclear Dna ◽  
Diploid Species ◽  
Nuclear Dna Content ◽  
Dna Amount ◽  
Nuclear Dna Amount ◽  
Speciation Event ◽  
Close Temporal Proximity

One of the intriguing issues concerning the dynamics of plant genomes is the occurrence of intraspecific variation in nuclear DNA amount. The aim of this work was to assess the ranges of intraspecific, interspecific, and intergeneric variation in nuclear DNA content of diploid species of the tribe Triticeae (Poaceae) and to examine the relation between life form or habitat and genome size. Altogether, 438 plants representing 272 lines that belong to 22 species were analyzed. Nuclear DNA content was estimated by flow cytometry. Very small intraspecific variation in DNA amount was found between lines of Triticeae diploid species collected from different habitats or between different morphs. In contrast to the constancy in nuclear DNA amount at the intraspecific level, there are significant differences in genome size between the various diploid species. Within the genus Aegilops , the 1C DNA amount ranged from 4.84 pg in A. caudata to 7.52 pg in A. sharonensis; among genera, the 1C DNA amount ranged from 4.18 pg in Heteranthelium piliferum to 9.45 pg in Secale montanum . No evidence was found for a smaller genome size in annual, self-pollinating species relative to perennial, cross-pollinating ones. Diploids that grow in the southern part of the group’s distribution have larger genomes than those growing in other parts of the distribution. The contrast between the low variation at the intraspecific level and the high variation at the interspecific one suggests that changes in genome size originated in close temporal proximity to the speciation event, i.e., before, during, or immediately after it. The possible effects of sudden changes in genome size on speciation processes are discussed.

scholarly journals Genome Size in Diploids, Allopolyploids, and Autopolyploids of Mediterranean Triticeae

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
T. Eilam ◽  
Y. Anikster ◽  
E. Millet ◽  
J. Manisterski ◽  
M. Feldman
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Nuclear Dna ◽  
Biological Significance ◽  
Physical Basis ◽  
Meiotic Behavior ◽  
Dna Amount ◽  
Nuclear Dna Amount ◽  
Tribe Triticeae ◽  
Natural And Synthetic

Nuclear DNA amount, determined by the flow cytometry method, in diploids, natural and synthetic allopolyploids, and natural and synthetic autopolyploids of the tribe Triticeae (Poaceae) is reviewed here and discussed. In contrast to the very small and nonsignificant variation in nuclear DNA amount that was found at the intraspecific level, the variation at the interspecific level is very large. Evidently changes in genome size are either the cause or the result of speciation. Typical autopolyploids had the expected additive DNA amount of their diploid parents, whereas natural and synthetic cytologically diploidized autopolyploids and natural and synthetic allopolyploids had significantly less DNA than the sum of their parents. Thus, genome downsizing, occurring during or immediately after the formation of these polyploids, provides the physical basis for their cytological diploidization, that is, diploid-like meiotic behavior. Possible mechanisms that are involved in genome downsizing and the biological significance of this phenomenon are discussed.

Genome size in 21 Artemisia L. species (Asteraceae, Anthemideae): Systematic, evolutionary, and ecological implications

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Montserrat Torrell ◽  
Joan Vallès
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Life Forms ◽  
Dna Amount ◽  
Ploidy Levels ◽  
Ecological Selection ◽  
Ecological Implications

Genome size was estimated by flow cytometry in 24 populations belonging to 22 Artemisia taxa (21 species, 1 with two subspecies), which represent the distinct subgenera, life forms, basic chromosome numbers, and ploidy levels in the genus. 2C nuclear DNA content values range from 3.5 to 25.65 pg, which represents a more than sevenfold variation. DNA content per haploid genome ranges from 1.75 to 5.76 pg. DNA amount is very well correlated with karyotype length and ploidy level. Some variations in genome size have systematic and evolutionary implications, whereas others are linked to ecological selection pressures.Key words: Artemisia, Asteraceae, flow cytometry, genome size, nuclear DNA amount variation, systematics, evolution, ecology.

Variation of DNA amount in 47 populations of the subtribe Artemisiinae and related taxa (Asteraceae, Anthemideae): karyological, ecological, and systematic implications

Genome ◽  
2004 ◽  
Vol 47 (6) ◽  
pp. 1004-1014 ◽  
Author(s):  
Sònia Garcia ◽  
María Sanz ◽  
Teresa Garnatje ◽  
Agnieszka Kreitschitz ◽  
E Durant McArthur ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Nuclear Dna ◽  
Evolutionary Relationships ◽  
Dna Amount ◽  
Basic Chromosome ◽  
Nuclear Dna Amount ◽  
C Value ◽  
Size Estimates

Genome size has been estimated by flow cytometry in 47 populations of 40 species of the tribe Anthemideae (Asteraceae), mainly from Artemisia and other genera of the subtribe Artemisiinae and related taxa. A range of 2C values from 3.54 to 21.22 pg was found. DNA amount per basic chromosome set ranged from 1.77 to 7.70 pg. First genome size estimates are provided for one subtribe, 10 genera, 32 species, and two subspecies. Nuclear DNA amount correlated well with some karyological, physiological and environmental characters, and has been demonstrated as a useful tool in the interpretation of evolutionary relationships within Artemisia and its close relatives.Key words: Artemisia, C value, ecology, evolution, flow cytometry, genome size, nuclear DNA amount variation, phylogeny, polyploidy, systematics.

First estimates of genome size in ribbon worms (phylum Nemertea) using flow cytometry and Feulgen image analysis densitometry

2014 ◽  
Vol 92 (10) ◽  
pp. 847-851 ◽  
Author(s):  
Kelly L. Mulligan ◽  
Terra C. Hiebert ◽  
Nicholas W. Jeffery ◽  
T. Ryan Gregory
Keyword(s):  
Flow Cytometry ◽  
Image Analysis ◽  
Body Size ◽  
Genome Size ◽  
Positive Relationship ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Size Estimation ◽  
Size Diversity ◽  
Size Estimates

Ribbon worms (phylum Nemertea) are among several animal groups that have been overlooked in past studies of genome-size diversity. Here, we report genome-size estimates for eight species of nemerteans, including representatives of the major lineages in the phylum. Genome sizes in these species ranged more than fivefold, and there was some indication of a positive relationship with body size. Somatic endopolyploidy also appears to be common in these animals. Importantly, this study demonstrates that both of the most common methods of genome-size estimation (flow cytometry and Feulgen image analysis densitometry) can be used to assess genome size in ribbon worms, thereby facilitating additional efforts to investigate patterns of variability in nuclear DNA content in this phylum.

The genome sizes of Hordeum species show considerable variation

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 730-735 ◽  
Author(s):  
Juha Kankanpää ◽  
Alan H. Schulman ◽  
Leena Mannonen
Keyword(s):  
Flow Cytometry ◽  
Hordeum Vulgare ◽  
Genome Size ◽  
Nuclear Dna ◽  
Size Variation ◽  
Nuclear Dna Content ◽  
Meiotic Pairing ◽  
Genome Size Variation ◽  
Dapi Staining ◽  
Hordeum Vulgare Ssp

Hordeum, distributed worldwide in temperate zones, is the second largest genus in the tribe Triticeae and includes diploid, tetraploid, and hexaploid species. We determined, by DAPI staining and flow cytometry, the nuclear DNA content for 35 accessions of the genus Hordeum, from a total of 19 species, including specimens of 2 cultivars and 2 landraces of Hordeum vulgare ssp. vulgare as well as samples of 12 Hordeum vulgare ssp. spontaneum populations. Genome sizes ranged from 5.69 to 9.41 pg for the G1 nuclei of the diploids, and from 13.13 to 18.36 pg for those of the tetraploids. This constitutes a 1.7-fold variation for the diploids, contrasting with a 4% variation previously reported. For H. vulgare ssp. vulgare (barley), the accessions examined differed by 18%. These variations in genome size cannot be correlated with meiotic pairing groups (I, H, X, Y) or with proposed phylogenetic relationships within the genus. Genome size variation between barley accessions cannot be related to status as cultivated or wild, or to climatic or geological gradients. We suggest these data may indicate rapid but sporadic changes in genome size within the genus. Key words : barley, Hordeum, Triticeae, genome size, flow cytometry.

Nuclear DNA content of the whitefly Bemisia tabaci (Aleyrodidae: Hemiptera) estimated by flow cytometry

2005 ◽  
Vol 95 (4) ◽  
pp. 309-312 ◽  
Author(s):  
J.K. Brown ◽  
G.M. Lambert ◽  
M. Ghanim ◽  
H. Czosnek ◽  
D.W. Galbraith
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Bemisia Tabaci ◽  
Dna Content ◽  
Blood Cells ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosome Counting ◽  
Male And Female ◽  
Haploid Genome Size

AbstractThe nuclear DNA content of the whitefly Bemisia tabaci (Gennnadius) was estimated using flow cytometry. Male and female nuclei were stained with propidium iodide and their DNA content was estimated using chicken red blood cells and Arabidopsis thaliana L. (Brassicaceae) as external standards. The estimated nuclear DNA content of male and female B. tabaci was 1.04 and 2.06 pg, respectively. These results corroborated previous reports based on chromosome counting, which showed that B. tabaci males are haploid and females are diploid. Conversion between DNA content and genome size (1 pg DNA = 980 Mbp) indicate that the haploid genome size of B. tabaci is 1020 Mbp, which is approximately five times the size of the genome of the fruitfly Drosophila melanogaster Meigen. These results provide an important baseline that will facilitate genomics-based research for the B. tabaci complex.

scholarly journals Genome Sizes in Hepatica Mill: (Ranunculaceae) Show a Loss of DNA, Not a Gain, in Polyploids

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
B. J. M. Zonneveld
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Dna Content ◽  
Close Relationships ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Dna Contents ◽  
Asiatic Species ◽  
Nuclear Dna Contents ◽  
Allotetraploid Species

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.

scholarly journals Evolution of Genome Size in Duckweeds (Lemnaceae)

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wenqin Wang ◽  
Randall A. Kerstetter ◽  
Todd P. Michael
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Propidium Iodide ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Continuous Increase ◽  
Spirodela Polyrhiza ◽  
Wolffia Arrhiza ◽  
Basic Reference

To extensively estimate the DNA content and to provide a basic reference for duckweed genome sequence research, the nuclear DNA content for 115 different accessions of 23 duckweed species was measured by flow cytometry (FCM) stained with propidium iodide as DNA stain. The 1C-value of DNA content in duckweed family varied nearly thirteen-fold, ranging from 150 megabases (Mbp) in Spirodela polyrhiza to 1,881 Mbp in Wolffia arrhiza. There is a continuous increase of DNA content in Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia that parallels a morphological reduction in size. There is a significant intraspecific variation in the genus Lemna. However, no such variation was found in other studied species with multiple accessions of genera Spirodela, Landoltia, Wolffiella, and Wolffia.

scholarly journals NUCLEAR DNA CONTENT IN BLUEBERRY DETERMINED BY FLOW CYTOMETRY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 580e-580
Author(s):  
Rodomiro Ortiz ◽  
D.E. Costich ◽  
T.P. Meagher ◽  
N. Vorsa
Keyword(s):  
Flow Cytometry ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Haploid Genome ◽  
Dna Flow Cytometry ◽  
Dna Amount ◽  
Ploidy Levels ◽  
Polyploid Evolution ◽  
Haploid Genome Size

DNA flow cytometry was used to determine nuclear DNA content in diploid blueberry species, and 3x, 4x, 5x, and 6x ploidy levels. Relative fluorescence intensity of stained nuclei measured by flow cytometry was a function of the number of chromosome sets (X): Y = 3.7X – 2.3 (r2 = 95.1%). DNA flow cytometry should be useful for ploidy level determination in the seedling stage. A significant linear relationship was established between nuclear DNA content and number of chromosomes (x); DNA (pg) = 0.52 x1 (r2 = 99.8%). Based on this equation the haploid genome DNA amount (1C) was calculated as 0.62 ± 0.08 pg, with an approximate haploid genome size of 602 Mbp/1C. The results indicate that conventional polyploid evolution occured in the section Cyanococcus, genus Vaccinium: the increase in DNA was concurrent with increase in chromosome number. DNA content differences among 2x species were correlated with Nei's genetic distance estimates based on 20 isozyme markers. Most of the variation was among species (49%), with 26% between populations within species, and 25% within populations.

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