Variation in Ribosomal DNA in the Genus Trifolium (Fabaceae)

The genus Trifolium L. is characterized by basic chromosome numbers 8, 7, 6, and 5. We conducted a genus-wide study of ribosomal DNA (rDNA) structure variability in diploids and polyploids to gain insight into evolutionary history. We used fluorescent in situ hybridization to newly investigate rDNA variation by number and position in 30 Trifolium species. Evolutionary history among species was examined using 85 available sequences of internal transcribed spacer 1 (ITS1) of 35S rDNA. In diploid species with ancestral basic chromosome number (x = 8), one pair of 5S and 26S rDNA in separate or adjacent positions on a pair of chromosomes was prevalent. Genomes of species with reduced basic chromosome numbers were characterized by increased number of signals determined on one pair of chromosomes or all chromosomes. Increased number of signals was observed also in diploids Trifolium alpestre and Trifolium microcephalum and in polyploids. Sequence alignment revealed ITS1 sequences with mostly single nucleotide polymorphisms, and ITS1 diversity was greater in diploids with reduced basic chromosome numbers compared to diploids with ancestral basic chromosome number (x = 8) and polyploids. Our results suggest the presence of one 5S rDNA site and one 26S rDNA site as an ancestral state.

Download Full-text

Cytotaxonomy of Allium (Amaryllidaceae) subgenera Cyathophora and Amerallium sect. Bromatorrhiza

Phytotaxa ◽

10.11646/phytotaxa.331.2.3 ◽

2017 ◽

Vol 331 (2) ◽

pp. 185 ◽

Cited By ~ 3

Author(s):

MIN-JIE LI ◽

XIAN-LIN GUO ◽

JUAN LI ◽

SONG-DONG ZHOU ◽

QING LIU ◽

...

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Karyotype Evolution ◽

Diploid Species ◽

Basic Chromosome Number ◽

Molecular Evidence ◽

Basic Chromosome ◽

Karyotype Asymmetry

In the present study, we examined the karyotype data of subg. Cyathophora and sect. Bromatorrhiza, to determine some disputed karyotypes (e.g., A. spicatum and A. fasciculatum), and further to estimate the karyotype evolution along their phylogenetic frameworks. Our results revealed a fairly stable basic chromosome number (x = 8) in subg. Cyathophora, and we therefore revised x = 8 as the basic chromosome number of A. spicatum, rather than x = 10 mostly due to misidentifications concerning A. fasciculatum. The karyotype asymmetry analyses for subg. Cyathophora indicated that, the karyotype evolution for diploid species showing a high karyotype similarity was mainly due to intrachromosomal changes, while the interchromosomal changes were linked to the evolution of tetraploid populations. However, indeed different dysploid basic chromosome numbers (x = 7, 10, 11) and greatly different karyotype patterns occurred in sect. Bromatorrhiza, corresponding to the subsections revealed by molecular evidence. The combined evidence suggested that species with x = 11 compose a segmental allotriploid complex. It was also indicated that karyotype pattern of polyploids usually is closely related with their diploid progenitors.

Download Full-text

Chromosome in situ hybridisation of ribosomal DNA in Erianthus sect. Ripidium species with varying chromosome numbers confirms x = 10 in Erianthus sect. Ripidium

Genome ◽

10.1139/g98-126 ◽

1999 ◽

Vol 42 (2) ◽

pp. 270-273 ◽

Cited By ~ 2

Author(s):

P Besse ◽

C L McIntyre

Keyword(s):

Chromosome Number ◽

Ribosomal Dna ◽

Chromosome Numbers ◽

In Situ Hybridisation ◽

Basic Chromosome Number ◽

Dna Probe ◽

Published Data ◽

Basic Chromosome ◽

Fluorescent In Situ Hybridisation

A wheat ribosomal DNA probe was used to determine the number of rDNA-carrying chromosomes in 2 Erianthus sect. Ripidium species using FISH (fluorescent in situ hybridisation) and non-fluorescent ISH. Two and four ribosomal DNA sites were revealed in E. elephantinus (2n = 20) and E. procerus (2n = 40), respectively. This result, together with previously published data showing 6 rDNA-carrying chromosomes in E. arundinaceus (2n = 60), confirms a possible basic chromosome number of x = 10 in Erianthus sect. Ripidium.Key words: Erianthus, FISH, ISH, ribosomal DNA, Saccharum, sugarcane.

Download Full-text

Reconstructing ancestral chromosome numbers and inflorescence features in Eleusininae (Poaceae: Chloridoideae: Cynodonteae)

Botanical Journal of the Linnean Society ◽

10.1093/botlinnean/boaa015 ◽

2020 ◽

Vol 193 (3) ◽

pp. 402-418

Author(s):

Raquel B Chiavegatto ◽

Angelino Carta ◽

Diego G S Pereira ◽

Flavio R G Benites ◽

Vânia H Techio ◽

...

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Evolutionary History ◽

Basic Chromosome Number ◽

High Rate ◽

Recent Common Ancestor ◽

Basic Chromosome ◽

Most Recent Common Ancestor ◽

Chromosome Number Evolution ◽

History Of

Abstract The chromosome number in Poaceae has changed widely over 77 Myr of evolution and polyploidization. Chromosome number changes can suggest a high rate of diversification and evolutionary novelties, and such changes can contribute to speciation. Despite this, chromosome numbers alone do not allow the evolutionary history of a group to be traced. Combined phylogenetic and karyological analyses can clarify the evolutionary history of taxa and allow taxonomic relationships and hierarchical levels to be inferred. The subtribe Eleusininae is the largest of the subfamily Chloridoideae. This study aims to reconstruct their chromosome number evolution, for which ChromEvol 2.0 software was used. Haploid chromosome numbers of Eleusininae were retrieved from the literature, and a consensus phylogenetic tree of Eleusininae was reconstructed. It was possible to infer 41 events of chromosome rearrangements along the evolutionary history of Eleusininae, according to the probabilistic model used. Chromosome number evolution in Eleusininae was mainly influenced by polyploidy events. The ancestral basic chromosome number for Eleusininae was p = 6, but the most recent common ancestor showed p2 = 10. In addition, some derived basic chromosome numbers, such as x = 9, arose through dysploidy, whereas x = 20 was generated via polyploidy.

Download Full-text

Relations and evolution in Cheilanthes (Sinopteridaceae, Pteridophita) in Macaronesia and Mediterranean area, deduced from genome analysis of their hybrids

Acta Botanica Malacitana ◽

10.24310/actabotanicaabmabm.v8i.9648 ◽

1983 ◽

Vol 8 ◽

pp. 101-126 ◽

Cited By ~ 2

Author(s):

G. Vida ◽

A. Major ◽

T. Reichstein

Keyword(s):

Chromosome Number ◽

Genome Analysis ◽

Chromosome Doubling ◽

Diploid Species ◽

Mediterranean Area ◽

Basic Chromosome Number ◽

The Other ◽

Experimental Conditions ◽

Natural Group ◽

Basic Chromosome

Nine species of "Cheilantoid ferns" are known to grow in Macaronesia and the Mediterranean basin. Two of them (lacking a pseudo-indusium and having the basic chromosome number X = 29), both aggregate species which we prefer to retain in Notholaena, are not included in this study. The other seven species (with distinct pseudo-indusium and the basic chromosome number X = 30), which we accept as members of the genus Cheilanthes Sw. sensu stricto, were subjected to detailed genome analysis of their natural and experimentally produced hybrids and shown to represent an aggregate of four very distinct ancestral diploids and three allotetraploids. The latter must have once been formed by chromosome doubling in the three diploid hybrids of C. maderensis Lowe with the other three diploid species. Theoretically three more allotetraploids would be possible but their formation has obviously been prevented by the geographical separation of the three respective diploids. The most widely distributed of the tetraploids, i.e. C. pteridioides (Reich.) C.Chr. has also been resynthesized from its ancestors (still sympatric) under experimental conditions. The intermediate morphology of the allotetraploids (as compared with their diploid ancestors) is obviously the reason why their status and existence has so long escaped recognition in Europe. These seven species form a natural group and, in our opinion, should not be divided into sections.

Download Full-text

Chromosome studies on African plants. 9. Chromosome numbers in Ehrharta (Poaceae: Ehrharteae)

Bothalia ◽

10.4102/abc.v19i1.948 ◽

1989 ◽

Vol 19 (1) ◽

pp. 125-132 ◽

Cited By ~ 2

Author(s):

J. J. Spies ◽

E. J. L. Saayman ◽

S. P. Voges ◽

G. Davidse

Keyword(s):

Chromosome Number ◽

Ploidy Level ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

B Chromosomes ◽

Basic Chromosome ◽

Cytogenetic Studies ◽

African Plants ◽

First Time

Cytogenetic studies of 53 specimens of 14 species of the genus Ehrharta Thunb. confirmed a basic chromosome number of 12 for the genus. Chromosome numbers for 13 species are described for the first time. The highest ploidy level yet observed in the genus (2n = lOx = 120) is reported for E. villosa var. villosa. B chromosomes were observed in several specimens of four different species.

Download Full-text

The biosystematics of the genus Lotus (Leguminosae) in Canada. II. Numerical chemotaxonomy

Canadian Journal of Botany ◽

10.1139/b68-084 ◽

1968 ◽

Vol 46 (5) ◽

pp. 585-589 ◽

Cited By ~ 19

Author(s):

William F. Grant ◽

Ilse I. Zandstra

Keyword(s):

Chromosome Number ◽

Thin Layer ◽

Native Species ◽

Cytological Study ◽

Diploid Species ◽

Basic Chromosome Number ◽

Chromatographic Study ◽

Chemical Identification ◽

Basic Chromosome ◽

Fluorescent Compounds

A thin-layer chromatographic study of fluorescent compounds present in native (L. denticulatus, L. formosissimus, L. micranthus, L. pinnatus, L. purshianus) and introduced (L. corniculatus, L. krylovii, L.pedunculatus, L. tenuis) Canadian species of Lotus has been carried out and relationships of the species have been determined on the basis of the coefficients of association of these compounds. Chemical identification of the compounds was not attempted, but test reagents indicated a number to be phenolics. The analysis supported the general taxonomic relationships of the species based on a morphological and cytological study. Of the native species, L. pinnatus and L. formosissimus were the most closely related, with a coefficient of association of 83.33. Lotus denticulatus, the only native species with a chromosome number of n = 6, in general showed lower coefficients of association with the n = 7 species. Of the introduced species, all of which belong to the L. corniculatus group with a basic chromosome number of 6, L. krylovii and L. tenuis had the highest coefficient of association, 75.86. Based on their coefficients of association, both of these diploid species were more closely related to the tetraploid L. corniculatus than to the diploid L. pedunculatus.

Download Full-text

Chromosome numbers in some species of Trifolium

Australian Journal of Agricultural Research ◽

10.1071/ar9690883 ◽

1969 ◽

Vol 20 (5) ◽

pp. 883 ◽

Cited By ~ 11

Author(s):

AJ Pritchard

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

First Time

The chromosome numbers of 31 species of Trifolium are reported, 18 for the first time. A reduction in basic chromosome number has occurred only in the three most highly specialized subgenera, and polyploids occur mainly in one of the more primitive subgenera.

Download Full-text

Fertility of Triploid Highbush Blueberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.116.2.336 ◽

1991 ◽

Vol 116 (2) ◽

pp. 336-341 ◽

Cited By ~ 15

Author(s):

N. Vorsa ◽

James R. Ballington

Keyword(s):

Gene Transfer ◽

Chromosome Number ◽

Chromosome Numbers ◽

2N Gametes ◽

Basic Chromosome Number ◽

Highbush Blueberry ◽

Pollen Stainability ◽

Frequency Distributions ◽

Basic Chromosome ◽

2N Gamete

Eight highbush blueberry (V. corymbosum L.) triploids (2n = 3x = 36) were crossed with diploids (2n = 2x = 24), tetraploids (2n = 4x = 48), and hexaploids (2n = 6x = 72). No plants were recovered from 4021 3x × 2x crosses. One triploid was relatively fertile in 3x × 4x and 3x × 6x crosses, which is most likely attributable to 2n gamete production in the triploid. The lack of fertility of triploids, which do not produce 2n gametes, in crosses with diploids and tetraploids suggests that the production of gametes with numerically balanced (n = 12 or 24) chromosome numbers is extremely low. In addition, the inability to recover progeny from 3x × 2x crosses also suggests that aneuploid gametophytes and/or zygotes, including trisomics, are inviable in blueberry. Pollen stainability was also highly reduced in triploids. Frequency distributions of anaphase I pole chromosomal constitutions of three triploids were significantly different from one another. Two of the three distributions were shifted toward the basic chromosome number of 12, with one triploid having 25% poles with 12 chromosomes. However, the sterility of 3x × 2x and 2x × 3x crosses indicates that lagging chromosomes during meiotic anaphases are probably not excluded from gametes, resulting in unbalanced gametes in blueberry. Triploids can be used as a bridge to facilitate gene transfer from the diploid and tetraploid levels to the hexaploid level in blueberry.

Download Full-text

Phylogenetics and chromosomal evolution in the Poaceae (grasses)

Australian Journal of Botany ◽

10.1071/bt03103 ◽

2004 ◽

Vol 52 (1) ◽

pp. 13 ◽

Cited By ~ 39

Author(s):

Khidir W. Hilu

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Chromosome Doubling ◽

Chromosomal Evolution ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

Wide Range ◽

The Family

The wide range in basic chromosome number (x = 2–18) and prevalence of polyploidy and hybridisation have resulted in contrasting views on chromosomal evolution in Poaceae. This study uses information on grass chromosome number and a consensus phylogeny to determine patterns of chromosomal evolution in the family. A chromosomal parsimony hypothesis is proposed that underscores (1) the evolution of the Joinvilleaceae/Ecdeiocoleaceae/Poaceae lineage from Restionaceae ancestors with x = 9, (2) aneuploid origin of x�=�11 in Ecdeiocoleaceae and Poaceae (Streptochaeta, Anomochlooideae), (3) reduction to x = 9, followed by chromosome doubling within Anomochlooideae to generate the x = 18 in Anomochloa, and (4) aneuploid increase from the ancestral x = 11 to x = 12 in Pharoideae and Puelioideae, and further diversification in remaining taxa (Fig. 3b). Higher basic chromosome numbers are maintained in basal taxa of all grass subfamilies, whereas smaller numbers are found in terminal species. This finding refutes the 'secondary polyploidy hypothesis', but partially supports the 'reduction hypothesis' previously proposed for chromosomal evolution in the Poaceae.

Download Full-text

Chromosome numbers of selected species of Elatine L. (Elatinaceae)

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2015.036 ◽

2015 ◽

Vol 84 (4) ◽

pp. 413-417 ◽

Cited By ~ 2

Author(s):

Anna Kalinka ◽

Gábor Sramkó ◽

Orsolya Horváth ◽

Attila Molnár V. ◽

Agnieszka Popiela

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

First Time

The paper reports chromosome numbers for 13 taxa of Elatine L., including all 11 species occurring in Europe, namely E. alsinastrum, E. ambigua, E. brachysperma, E. brochonii, E. californica, E. campylosperma, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma, E. triandra originating from 17, field-collected populations. For seven of them (E. ambigua, E. californica, E. campylosperma, E. brachysperma, E. brochonii, E. hungarica, E. orthosperma) the chromosome numbers are reported for the first time. With these records, chromosome numbers for the whole section Elatinella Seub. became available. Although 2n = 36 was reported to be the most common and the lowest chromosome number in the genus, our data show that out of thirteen species analyzed, six had 36 chromosomes but five species had 54 chromosomes, and the lowest number of chromosomes was 18. These data further corroborates that the basic chromosome number in Elatine is x = 9.

Download Full-text