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

2015 ◽  
Vol 84 (4) ◽  
pp. 413-417 ◽  
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 <em>Elatine</em> L., including all 11 species occurring in Europe, namely <em>E. alsinastrum</em>, <em>E. ambigua</em>, <em>E. brachysperma</em>, <em>E. brochonii</em>, <em>E. californica</em>, <em>E. campylosperma</em>, <em>E. gussonei</em>, <em>E. hexandra</em>, <em>E. hungarica</em>, <em>E. hydropiper</em>, <em>E. macropoda</em>, <em>E. orthosperma</em>, <em>E. triandra</em> originating from 17, field-collected populations. For seven of them (<em>E. ambigua</em>, <em>E. californica</em>, <em>E. campylosperma</em>, <em>E. brachysperma</em>, <em>E. brochonii</em>, <em>E. hungarica</em>, <em>E. orthosperma</em>) the chromosome numbers are reported for the first time. With these records, chromosome numbers for the whole section <em>Elatinella</em> Seub. became available. Although 2<em>n</em> = 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 <em>Elatine</em> is <em>x</em> = 9.

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

Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 125-132 ◽  
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.

Chromosome numbers in some species of Trifolium

1969 ◽  
Vol 20 (5) ◽  
pp. 883 ◽  
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.

scholarly journals Cytotaxonomic Study of Hypodematium (Hypodematiaceae) from China

Phytotaxa ◽  
2014 ◽  
Vol 161 (2) ◽  
pp. 101 ◽  
Author(s):  
Renxiang Wang ◽  
Wen Shao ◽  
Ling Liu
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Habitat Preferences ◽  
Northeast Asia ◽  
Basic Chromosome Number ◽  
Basic Chromosome ◽  
Dry Conditions ◽  
Diakinesis Stage ◽  
First Time ◽  
Meiosis I

Chromosome numbers and reproductive biology of nine species of the fern genus Hypodematium (Hypodematiaceae) from China were investigated. The chromosome numbers of eight species are reported here for the first time: H. daochengensis n=41 (41 II); H. fordii n=40 (40 II), n=80 (40 II+40 I), 2n=120; H. glanduloso-pilosum n=41 (41 II), 2n=82, 2n=123; H. gracile n=41 (41 II); H. hirsutum n= 41 (41 II); H. microleptoides n=41 (41 II); H. sinense n= 40 (40 II) and H. squamuloso-pilosum n=41 (41 II). Two cytotypes, n=82 (41 II+41 I) and 2n=123 in H. crenatum, are reported for the first time.  Our results showed that the species with these cytotypes are agamospermous triploids: H. crenatum n = 82 (41 II +41 I), H. glanduloso-pilosum n = 82 (41 II +41 I) and H. fordii n = 80 (40 II +40 I), based on the unequal size and presence of aborted spores in the sporangium, and the allotriploid hybrid chromosomes in the spore mother cell at the diakinesis stage of meiosis I. The remaining species are sexual diploids and tetraploids, based on the chromosome number n = 41 and n =82 at the diakinesis stage of meiosis I of spore mother cells. The relationships among habitat preferences, frond hairs and reproductive modes in Hypodematium are discussed and illustrated. It appears that plants with large fronds and sparse, thin hairs, living in humid and shady places undergo sexual reproduction, while small plants living in sunny and dry conditions with thick hairs undergo agamospermous reproduction. The distribution pattern and basic chromosome number all indicated the basic chromosome number x= 41 was plesiomorphic, whereas x=40 was apomorphic. Chromosome aneuploid changes occurred in this genus. The distribution of the sexual diploids and tetraploids and agamospermous triploids suggests that the genus might have originated in the Himalayas and dispersed from there to northeast Asia and Japan.

scholarly journals A taxonomic study on Centaurea sect. Rhizocalathium and C. sect. Pseudoseridia (Asteraceae, Cardueae–Centaureinae) in Iran

Phytotaxa ◽  
2014 ◽  
Vol 174 (1) ◽  
pp. 43 ◽  
Author(s):  
Kazem Negaresh ◽  
MOHAMMAD REZA RAHIMINEJAD ◽  
MASSOUD RANJBAR
Keyword(s):  
Chromosome Number ◽  
Basic Chromosome Number ◽  
New Combination ◽  
Taxonomic Study ◽  
Basic Chromosome ◽  
New Subspecies ◽  
Taxonomic Review ◽  
First Time

A taxonomic review of Centaurea sect. Rhizocalathium Tzvelev and C. sect. Pseudoseridia Wagenitz in Iran was carried out. The latter, with only one species, Centaurea stevenii, is reported here as new to Iran. In Centaurea sect. Rhizocalathium, C. lasiorhiza is treated as a correct name, C. ispahanica subsp. sirjanensis is described as a new subspecies and C. ispahanica subsp. macrocarpa is proposed as a new combination. Finally, C. ispahanica is typified and its chromosome number is reported for the first time, and a new basic chromosome number for C. sect. Rhizocalathium is proposed.

scholarly journals Fertility of Triploid Highbush Blueberry

1991 ◽  
Vol 116 (2) ◽  
pp. 336-341 ◽  
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.

Alteration of basic chromosome number by fusion–fission cycles

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1289-1292 ◽  
Author(s):  
Ingo Schubert ◽  
Rigomar Rieger ◽  
Jörg Fuchs
Keyword(s):  
Chromosome Number ◽  
Vicia Faba ◽  
Karyotype Evolution ◽  
Basic Chromosome Number ◽  
Metacentric Chromosome ◽  
Field Bean ◽  
Basic Chromosome ◽  
Chromosome I ◽  
First Time

A complete chromosomal fusion–fission cycle is described for the first time. In the field bean, Vicia faba, this cycle probably started with a reversible fusion of two telocentrics giving rise to the standard metacentric chromosome I. The next step was a recent fission of this chromosome into two stable telocentrics eventually followed by a new fusion reconstituting the metacentric chromosome.Key words: karyotype evolution, chromosome number, chromosomal fusion–fission cycle, Vicia faba.

Phylogenetics and chromosomal evolution in the Poaceae (grasses)

2004 ◽  
Vol 52 (1) ◽  
pp. 13 ◽  
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.

scholarly journals Cytological Investigation of Brazilian Nightshade (Solanum seaforthianam Andr.)

2014 ◽  
Vol 15 ◽  
pp. 44-48
Author(s):  
D. Jagatheeswari
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Complement ◽  
Basic Chromosome Number ◽  
Cytological Investigation ◽  
Ancestral Species ◽  
Basic Chromosome ◽  
Centromere Position ◽  
Solanaceae Family

Solanum genus namely Solanum seaforthianum Andr. belongs to the Solanaceae family, and comprises only dioeciously species. These plants are distributed between 29º and 40º south. All species of this genus are diploid with chromosome numbers of 2n = 24, 28 and 30. According to literature, the basic chromosome number in this genus is x = 12, 14 and 15. Solanum genus with a chromosome complement of 2n = 30 has a symmetric karyotype with a median and sub median centromere position. Because ancestral species have a symmetric karyotype, it seems that x = 12 is the initial basic chromosome number in this genus and the x = 14 and x = 15 derived from x = 12. So it seems that diploid phenomena played an important role in evolution and speciation

scholarly journals Karyotype evolution of the genus Eranthis Salisb. (Ranunculaceae)

2020 ◽  
Vol 19 (2) ◽  
pp. 056-060
Author(s):  
E. Yu Mitrenina ◽  
A. S. Erst
Keyword(s):  
Chromosome Number ◽  
Comparative Study ◽  
Karyotype Evolution ◽  
Basic Chromosome Number ◽  
B Chromosomes ◽  
Basic Chromosome ◽  
Meristematic Cells ◽  
Pericentric Inversions ◽  
Root Meristematic Cells ◽  
First Time

We have conducted comparative study of karyotypes for nine Eranthis Salisb. species: E. bulgarica (Stef.)Stef., E. hyemalis (L.) Salisb., E. longistipitata Regel (section Eranthis), E. byunsanensis B. Y. Sun, E. lobulata W. T.Wang, E. pinnatifida Maxim., E. sibirica DC., E. stellata Maxim., and E. tanhoensis Erst (section Shibateranthis). Thespecies-specifity of karyotypes was established for all species investigated. The chromosomes of each species weremedium or large in size (4–12 µm). Besides E. sibirica and E. tanhoensis, all the investigated specimens had diploidcytotypes with 2n = 16 and the basic chromosome number x = 8. Plants from five E. sibirica populations were tetraploidand hexaploid with x = 7, 2n = 28 and 2n = 42 respectively. Plants from seven E. tanhoensis populations were diploid withx = 7 and 2n = 14. Diploid karyotypes of Eranthis included 4–5 pairs of large equal-armed (metacentric) chromosomes,and 2–4 pairs of unequal-armed chromosomes belonging to different morphological types (submetacentric, subtelocentric,and acrocentric ones). We have revealed B chromosomes in root meristematic cells of E. lobulata and E. tanhoensis forthe first time. We suppose that the key developments in Eranthis karyotype`s evolution were pericentric inversions,polyploidy, and probably translocations.

scholarly journals Chromosome Numbers of Rubus Species at the National Clonal Germplasm Repository

HortScience ◽  
1995 ◽  
Vol 30 (7) ◽  
pp. 1447-1452 ◽  
Author(s):  
Maxine M. Thompson
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Agricultural Research ◽  
Basic Chromosome Number ◽  
Ploidy Levels ◽  
Basic Chromosome ◽  
Rubus Species ◽  
Agricultural Research Service ◽  
The U.S ◽  
Research Service

The U.S. Dept. of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR), Corvallis, Ore., maintains Rubus germplasm representing worldwide diversity of the genus. Chromosome numbers were counted for 201 plants representing 124 taxa (species and varieties). There are new reports for 42 taxa, confirmation for 72 previously reported, and 10 counts for plants unidentified to species. The basic chromosome number was seven, and ploidy levels ranged from 2x to 12x.

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