STUDIES ON THE GENOME CONSTITUTION OF TRITICUM TIMOPHEEVI ZHUK: III. SEGREGATION OF MEIOTIC CHROMOSOME BEHAVIOUR IN BACKCROSS GENERATIONS

1970 ◽  
Vol 12 (2) ◽  
pp. 347-355 ◽  
Author(s):  
E. B. Wagenaar
Keyword(s):  
Cytogenetic Analysis ◽  
Triticum Turgidum ◽  
Meiotic Chromosome ◽  
Successive Generation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Genome Constitution ◽  
Triticum Timopheevi ◽  
Meiotic Irregularities

Cytogenetic analysis of three backcross generations of the hybrid Triticum turgidum × T. timopheevi (2n = 28) showed segregation of meiotic behaviour in each successive generation. The segregation was continuous and was possibly under control of polygenes. These results indicate that the meiotic irregularities commonly found in F1 hybrids between T. turgidum and T. timopheevi are primarly genetically induced.

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.

Persisting demibivalents: a unique meiotic behaviour in Cuscuta babylonica Choisy

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Batia Pazy ◽  
Uzi Plitmann
Keyword(s):  
Key Words ◽  
Chromosome Segregation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Chromosome Movement ◽  
Pollen Mother Cells ◽  
Key Words Meiosis ◽  
Mother Cells ◽  
Telomeric Association

Idiosyncratic chromosome behaviour during meiosis was found in pollen mother cells of Cuscuta babylonica Choisy, a thread-like holoparasitic herb. Its main features are among the following: (i) telomeric association between homologues through most stages of the process, which leads to persisting chromatid bivalents (= "demibivalents"); (ii) uncommon chromosome segregation in first and second anaphase; and (iii) prolonged intensified heterochromatinization. Although "regular" in its own way, this process leads to the formation of unviable products. Its further investigation might contribute to our understanding of the role of the spindle and chromosome movement in the ordinary process of meiosis. Key words: meiosis (abnormal), persisting demibivalents, Cuscuta babylonica.

Chromosome instability in wheat plants regenerated from suspension culture

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 627-629 ◽  
Author(s):  
George Fedak ◽  
K. C. Armstrong ◽  
R. J. Handyside
Keyword(s):  
Triticum Aestivum ◽  
Suspension Culture ◽  
Key Words ◽  
Chinese Spring ◽  
Meiotic Chromosome ◽  
Chromosome Instability ◽  
Wheat Chromosome ◽  
Chromosome Behaviour ◽  
Meiotic Configuration ◽  
Culture Suspension

Plants of Triticum aestivum cv. Chinese Spring were regenerated from 30 calli obtained from suspension cultures. All four plants showed abnormal meiotic chromosome behaviour relative to the control. The average meiotic configuration over all plants was 1.55 I + 18.16 II + 0.30 III + 0.82 IV. In addition, an isochromosome was frequently observed in cells of all plants, which was indicative of centromeric breaks. Key words: culture (suspension), wheat, chromosome instability.

Evidence on the origin of the G genome in wheat: cytology and fertility of a T. timopheevi-like mutant

1983 ◽  
Vol 25 (6) ◽  
pp. 651-661 ◽  
Author(s):  
U. Kushnir ◽  
G. M. Halloran
Keyword(s):  
Triticum Turgidum ◽  
Chromosome Rearrangement ◽  
Plant Morphology ◽  
Triticum Timopheevi ◽  
Somatic Mutant ◽  
Normal Pairing

A spontaneous somatic mutant with Triticum timopheevi Zhuk. plant morphology was found in late tillers of a Triticum turgidum L. var. dicoccoides (Bowden) plant. Hybrids of the timopheevi-like mutant with T. turgidum L. var. dicocooides (Bowden), T. timopheevi Zhuk., and T. araraticum Jakubz. exhibited irregular pairing at meiosis and sterility, almost normal pairing and fertility, and relatively high pairing and sterility, respectively. This evidence plus that of karyotype changes in the somatic mutant indicated that it was differentiated from T. turgidum dicoccoides through chromosome interchanges. This mutation, believed to arise through chromosome rearrangement, is discussed in relation to the origin of the G genome of T. timopheevi.

Sign in / Sign up

Export Citation Format

Share Document