Somatic Chromosome Counts from Leaf Meristems in the Tribe Triticeae

1984 ◽  
Vol 59 (4) ◽  
pp. 197-200 ◽  
Author(s):  
H. C. Sharma ◽  
B. S. Gill
Keyword(s):  
Somatic Chromosome ◽  
Chromosome Counts ◽  
Tribe Triticeae

A new species of Trigonella sect. Ellipticae (Leguminosae-Papilionoideae) from Iran, including cytogenetic and anatomical notes

Phytotaxa ◽  
2015 ◽  
Vol 202 (1) ◽  
pp. 26 ◽  
Author(s):  
Massoud Ranjbar ◽  
ZAHRA HAJMORADI
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Related Species ◽  
Somatic Chromosome ◽  
Base Number ◽  
Somatic Chromosome Number ◽  
Chromosome Counts ◽  
Closely Related Species ◽  
A New Species

A new species, Trigonella bakhtiarica, from the Iranian province Chahar Mahal Va Bakhtiari is described, illustrated and compared to its most closely related species, T. aphanoneura. Trigonella bakhtiarica has a longer corolla and differs in the shape, surface and size of its pods, which are taxonomically informative characters in Trigonella sect. Ellipticae. Chromosome counts and meiosis assays show that both species are diploid, and that their euploid plants possess a somatic chromosome number of 2n = 2x = 16, which is consistent with the predicted base number of x = 8.

scholarly journals A report on new chromosome number of three Dioscorea species

2019 ◽  
Vol 6 (2) ◽  
pp. 147-150
Author(s):  
Chiranjit Paul ◽  
Bimal Debnath
Keyword(s):  
Chromosome Number ◽  
Somatic Chromosome ◽  
Chromosome Count ◽  
Somatic Chromosome Number ◽  
Chromosome Counts ◽  
North East India ◽  
North East ◽  
Forest Belts ◽  
Dioscorea Species ◽  
First Time

Chromosomal study conducted in nine species of Dioscorea from different forest belts of Tripura revealed that their somatic chromosome number ranged from 2n=40 to 2n=60. The record of 2n=40 chromosome in the sexual phenotypes of Dioscorea hamiltonii, Dioscorea glabra and Dioscorea pubera are the first time report from Tripura, North East India. Moreover the somatic chromosome counts of 2n=60 in Dioscorea pentaphylla would be attributed as a new cytotype. However at the respective ploidy level no difference in somatic chromosome count was observed between their sexes.

Chromosome numbers in Craspedia, Ewartia and Pterygopappus (Compositae: Gnaphalieae)

1999 ◽  
Vol 12 (5) ◽  
pp. 671 ◽  
Author(s):  
Murray I. Dawson ◽  
Ilse Breitwieser ◽  
Josephine M. Ward
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Chromosome Counts

Somatic chromosome counts are documented for seven species of the Gnaphalieae (Compositae) from Australia: Craspedia alpina Backh. (2n= 10x2 = 110) and C. glauca (Labill.) Spreng. (2n= 4x2 = 44), Ewartia catipes (DC.) Beauverd, E. nubigena Beauverd and E. planchonii (Hook.f.) Beauverd (all 2n= 2x2 = 28), E. meredithiae (F.Muell.) Beauverd (2n= 4x2 = 56) and Pterygopappus lawrencei Hook.f. (2n = 2x2 = 28).

The cytology of hybrids between Hordeum vulgare and H. bulbosum revisited

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 486-494 ◽  
Author(s):  
Xu Jie ◽  
J. W. Snape
Keyword(s):  
Hordeum Vulgare ◽  
High Frequency ◽  
Interspecific Hybrids ◽  
Somatic Chromosome ◽  
Banding Technique ◽  
Chromosome 6 ◽  
Hordeum Bulbosum ◽  
Chromosome Counts ◽  
Low Frequencies ◽  
C Banding

Diploid and triploid interspecific hybrids were produced from crosses between four Hordeum vulgare varieties and two diploid and two tetraploid Hordeum bulbosum genotypes. These were studied cytologically using a C-banding technique as well as with conventional staining procedures. C-banding of mitotic preparations of the hybrids enabled all H. vulgare chromosomes to be identified individually, although only the satellited chromosome of H. bulbosum could be distinguished from the others of this genome. Most diploid hybrids had stable somatic chromosome constitutions (2n = 14), although 4 out of 39 plants had a mosaic constitution. Chromosome counts of triploid hybrids, however, revealed that about 40% of plants had a mosaic somatic constitution ranging from 7–22 chromosomes per cell, although 21-chromosome cells were at the highest frequency. Studies of meiosis in diploid hybrids showed that the frequency of pairing between H. vulgare and H. bulbosum chromosomes varied between different cross combinations and appeared to be mainly under the control of the H. bulbosum genome. C-banding revealed that H. vulgare chromosome 6 paired with the satellited chromosome of H. bulbosum. However, this latter chromosome was also absent in the majority of aneuploid cells and appeared to be the first to be eliminated. Meiosis in triploid hybrids was characterized by the presence of univalents, bivalents, and trivalents and, infrequently, higher order associations. Bivalents were formed mainly from pairing between H. bulbosum chromosomes alone, although trivalents were formed from pairing between two H. bulbosum and one H. vulgare chromosomes. All univalents, in cells that contained less than seven, were H. vulgare chromosomes. Overall, these results indicate that a high frequency of homoeologous allosyndesis can occur between the chromosomes of these two species, but it does depend on the H. bulbosum genotype used. It should be possible to introgress genes into H. vulgare through the use of H. bulbosum genotypes that have low frequencies of elimination and high chromosome pairing.Key words: Hordeum vulgare, H. bulbosum, C-banding, chromosome pairing.

An advanced generation of Aranda orchids

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 608-611 ◽  
Author(s):  
Y. H. Lee ◽  
F. Y. Tham
Keyword(s):  
Somatic Chromosome ◽  
Intergeneric Hybrids ◽  
Root Tip ◽  
Chromosome Counts ◽  
Pollen Mother Cells ◽  
Mother Cells ◽  
Tip Cells ◽  
Somatic Chromosome Numbers ◽  
Root Tip Cells ◽  
Advanced Generation

Aranda orchids are a group of artificially bred intergeneric hybrids between member species (2n = 38) of two natural genera, Vanda and Arachnis, of Orchidaceae. Nine second generation Aranda cultivars were selected for analysis of somatic chromosome numbers, meiotic behaviour, and sporad formation. Eight of the cultivars were derived from Aranda × Vanda crosses and one from an Aranda × Aranda cross. Chromosome counts of their root tip cells showed that eight of them contained 2n = 3x = 57 chromosomes each, presumably resulting from unreduced eggs of the Aranda parent fertilized by haploid Vanda pollen. The ninth revealed 2n = 2x = 38 chromosomes. Pollen mother cells of eight of the cultivars (2n = 3x = 57) commonly formed more than 10 bivalents, presumably between homologous Vanda chromosomes, as well as many univalents, mainly of Arachnis chromosomes. Only 8–10 bivalents were observed in pollen mother cells of the ninth cultivar (2n = 2x = 38). All the cultivars formed a range of dyads containing unreduced microspores. Two mechanisms are proposed for the origin of these dyad sporads.Key words: Aranda orchids, intergeneric hybrids, cytology.

Circaea × intermedia in eastern North America with particular reference to Ontario

1977 ◽  
Vol 55 (23) ◽  
pp. 2919-2935 ◽  
Author(s):  
Erich Haber
Keyword(s):  
North America ◽  
North American ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Somatic Chromosome ◽  
Parental Species ◽  
Eastern North America ◽  
Chromosome Counts ◽  
Morphological Differences ◽  
Somatic Chromosome Numbers

Circaea × intermedia Ehrh. in North America is an interspecific hybrid between C. alpina L. and C. lutetiana L. subsp. canadensis Aschers. & Magnus. In spite of the morphological differences that exist between the European and North American subspecies of C. lutetiana, hybrids from both continents are morphologically identical. Documentation of the intermediacy of the hybrid taxon is presented based on the evaluation of the means of 22 characters of specimens from an Ontario locality at which all three taxa are found.Diploid chromosome counts of 2n = 22 are reported for Ontario populations of the hybrid and parental species. The presence of irregular, somatic chromosome numbers are also reported for all three taxa.Distribution maps for all three taxa in eastern North America are included. In the case of C. lutetiana subsp. canadensis, the northern range is sharply delimited by the Precambrian–Paleozoic bedrock boundary.A table of character comparisons and a key to the three taxa summarizes the salient characteristics of the hybrid and the parental species in eastern North America.

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