Cytogenetic Studies in Lilium callosum. v. Supernumerary B Chromosomes in Wild Populations

Evolution ◽  
1962 ◽  
Vol 16 (2) ◽  
pp. 246 ◽  
Author(s):  
Hiroshi Kayano
Keyword(s):  
B Chromosomes ◽  
Wild Populations ◽  
Cytogenetic Studies

scholarly journals Transmission rate variation among three B chromosome variants in the fish Prochilodus lineatus (Characiformes, Prochilodontidae)

2013 ◽  
Vol 85 (4) ◽  
pp. 1371-1377 ◽  
Author(s):  
MANOLO PENITENTE ◽  
TATIANA A. VOLTOLIN ◽  
JOSE A. SENHORINI ◽  
JEHUD BORTOLOZZI ◽  
FAUSTO FORESTI ◽  
...  
Keyword(s):  
Transmission Rate ◽  
B Chromosome ◽  
B Chromosomes ◽  
Rate Variation ◽  
Parental Line ◽  
Prochilodus Lineatus ◽  
Extinction Process ◽  
Cytogenetic Studies ◽  
Acrocentric Chromosomes ◽  
Interesting System

Cytogenetic studies were developed in Prochilodus lineatus (Valenciennes 1836), describing an interesting system of small supernumerary chromosomes. The purpose of this work is to study the frequency and morphology of B chromosomes in individuals from the parental line and the inheritance patterns of these elements in individuals obtained from controlled crosses in the species P. lineatus. The transmission rate of B chromosomes revealed a kB=0.388 for the acrocentric type, a kB=0.507 for the metacentric type and a kB=0.526 for the submetacentric type. The obtained results raise hypothesis that B-acrocentric chromosomes are involved in an extinction process in this species, while the metacentric and submetacentric supernumerary elements comprises a neutral mechanism and follows a Mendelian transmission rate.

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.

Cytogenetic studies in relation to taxonomy within the family Gryllidae (Orthoptera). I. Subfamily Gryllinae

1973 ◽  
Vol 51 (2) ◽  
pp. 179-186 ◽  
Author(s):  
H.-C. Lim ◽  
V. R. Vickery ◽  
D. K. McE. Kevan
Keyword(s):  
Chromosome Number ◽  
Species Level ◽  
B Chromosomes ◽  
Chromosome Behavior ◽  
Generic Level ◽  
The Family ◽  
Cytogenetic Studies ◽  
Gryllus Campestris ◽  
And Behavior

Twelve species of Gryllinae were studied to determine the number, morphology and behavior of their chromosomes. The male diploid numbers ranged from 19 to 31. Gryllus campestris and a population of "G. bimaculatus" from Singapore showed anomalies in chromosome behavior and structure, including breaks, stickiness, C-mitosis, polyploidy, lagging, unequal segregation and non-disjunction in the former and many aberrations and loss of fertility in the latter. One or two B-chromosomes occurred in some individuals of G. veletis, the chromosome number of this species thus varying from 2n ♀ = 29 to 31. In the Gryllinae, karyotypic differences are shown to be more useful than chromosome number at the species level; differences in chromosome number are useful taxonomically at the generic level, when combined with differences in karyotypes.

The effect of B-chromosomes on chiasma frequency in wild populations of rye

Chromosoma ◽  
1969 ◽  
Vol 27 (2) ◽  
pp. 198-200 ◽  
Author(s):  
Lj. Zečević ◽  
Dobrila Paunović
Keyword(s):  
Chiasma Frequency ◽  
B Chromosomes ◽  
Wild Populations
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