scholarly journals Additional documented chromosome number determinations in Paysonia (Brassicaceae)

2021 ◽  
Vol 15 (2) ◽  
pp. 575-577
Author(s):  
Andrew M. Salywon ◽  
Jon P. Rebman ◽  
David A. Dierig
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome

Thirteen meiotic chromosome number determinations are reported for seven species of Paysonia O’Kane & Al-Shehbaz (Brassicaceae). Our counts are in agreement with previous published numbers and we make new chromosome number reports for five counties.

Meiotic chromosome behaviour in Cenchrus ciliaris

Bothalia ◽  
1998 ◽  
Vol 28 (1) ◽  
pp. 83-90 ◽  
Author(s):  
N. C. Visser ◽  
J. J. Spies
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Basic Chromosome Number ◽  
Chromosome Behaviour ◽  
Meiotic Abnormalities ◽  
Single Specimen ◽  
Cenchrus Ciliaris ◽  
Basic Chromosome ◽  
Single Genome ◽  
Meiotic Irregularities

A basic chromosome number of x = 9 has been confirmed for Cenchrus ciliaris L. Polyploidy is common and levels vary from tetraploid to hexaploid. Aneuploidv is reported for a single specimen, where two chromosomes of a single genome were lost. Various meiotic irregularities were observed. The highest incidence of meiotic abnormalities was observed in the pentaploid specimens. This was attributed to their uneven polyploid level All specimens varied from segmental alloploid to alloploid.

The chromosomes of Metachirus nudicaudatus (Marsupialia : Didelphidae)

1973 ◽  
Vol 21 (3) ◽  
pp. 369 ◽  
Author(s):  
E Yunis ◽  
J Cayon ◽  
E Ramirez
Keyword(s):  
Chromosome Number ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
Evolutionary History ◽  
Meiotic Chromosome ◽  
Staining Technique ◽  
Pachytene Stage ◽  
Apparent Lack ◽  
Heterochromatin Staining ◽  
Metachirus Nudicaudatus

A karyologic study of M. nudicaudatus, carried out on three females and five males, shows a chromosome number of 14, with apparent lack of dimorphism in the sex chromosomes. Nevertheless, the heterochromatin staining technique reveals the Y chromosome to be fully heteropycnotic. The meiotic chromosome has a sex vesicle at the pachytene stage. The similarity of this karyotype with those of Caluromys derbianus and Dromiciops australis is striking, especially considering that the genera belong to two subfamilies separated early in their evolutionary history. Our results support the opinion of Hayman and Martin that the original chromosome number in Marsupialia was 14.

Cytotaxonomic studies on some cyclopoid copepods (Copepoda, Crustacea) from Ontario, Canada

1979 ◽  
Vol 57 (8) ◽  
pp. 1597-1604 ◽  
Author(s):  
C. C. Chinnappa ◽  
Reginald Victor
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Mesocyclops Leuckarti ◽  
Mesocyclops Edax

The cytology of 10 Ontario species of cyclopoid copepods has been investigated. The chromosome number and meiotic chromosome behaviours are described for the females of Acanthocyclops vernalis (2n = 8), Acanthocyclops vernalis ssp. Parcus? (2n = 6), Tropocyclops prasinus mexicanus (2n = 11), Eucyclops setrulatus (2n = 13), Eucyclops speratus (2n = 13), Mesocyclops leuckarti (2n = 12), Mesocyclops edax (2n = 14), Macrocyclops albidus (2n = 14), Macrocyclops ater (2n = 22), and Diacyclops bicuspidatus thomasi (2n = 18). Cytotaxonomic implications in relation to the evolution in this group are discussed.

Meiotic chromosome number and behaviour ofOnobrychis alborzensis(Fabaceae): a new species from northern Iran

2011 ◽  
Vol 122 (7-8) ◽  
pp. 433-444 ◽  
Author(s):  
Massoud Ranjbar ◽  
Fatemeh Hajmoradi ◽  
Roya Karamian
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Northern Iran ◽  
A New Species

CYTOGENETIC, ECOLOGIC AND MORPHOLOGIC STUDIES IN BRAZILIAN FORMS OF PASPALUM NOTATUM

1973 ◽  
Vol 15 (3) ◽  
pp. 523-531 ◽  
Author(s):  
M. Irene B. De Moraes Fernandes ◽  
I. L. Barreto ◽  
F. M. Salzano
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
The Other ◽  
Paspalum Notatum ◽  
Meiotic Behavior ◽  
Ecological Data ◽  
Somatic Number ◽  
The Difference ◽  
Different Strains ◽  
Fair Degree

The somatic number, meiotic behavior, morphology and ecology of five forms of Paspalum notatum are reported. All of them showed a chromosome number of 2n = 40. There is a fair degree of variation in the frequencies of meiotic chromosome configurations in different strains of a given form, but for four of the five we could characterize them as showing about 2-3 IV and 14-16 II. The type Capivari presents distinct differences in relation to all others, with about 1 IV and 18 II. The prevalence of I and III is very low (about 0.1) in all forms investigated. The morphological and ecological data, in a general way, confirm the difference between Capivari and the other taxons.

scholarly journals Karyotypes and Morphological Variability of Crayfish Pontastacus Leptodactylus and P. Angulosus (Malacostraca, Decapoda)

2013 ◽  
Vol 47 (3) ◽  
pp. 11-16 ◽  
Author(s):  
V. S. Kostyuk ◽  
A. V. Garbar ◽  
S. V. Mezhzherin
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Morphological Variability ◽  
Nominal Species ◽  
Widespread Species ◽  
Haploid Chromosome Number ◽  
N 93

The existence on the territory of Ukraine of two sympatric widespread species definitely different by their chromosome number was proved based on the meiotic chromosome preparations. Besides the nominal species Pontastacus leptodactylus (Dana, 1852) with modal haploid chromosome number n = 93 we prove the existence of P. angulosus (Rathke, 1837) with n = 88.

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