The chromosomal location of a gene (msg) affecting megasporogenesis in durum wheat

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 578-581 ◽  
Author(s):  
L. R. Joppa ◽  
N. D. Williams ◽  
S. S. Maan
Keyword(s):  
Durum Wheat ◽  
Key Words ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Wheat Line ◽  
Pollen Mother Cells ◽  
Chromosome Arm ◽  
Pollen Nucleus ◽  
Mother Cells ◽  
Metaphase I

An aneuploid durum wheat line (Triticum turgidum L. var. durum) having 13 chromosome pairs and 2 unpaired chromosomes at metaphase I of meiosis in pollen mother cells (i.e., monosomic for chromosomes 7A and 7D) was observed to produce some progeny plants with 2n = 40 chromosomes. These aneuploid (triploid) plants were usually weak and sterile. Triploid plants also occurred in the progeny of durum plants monosomic for chromosome 7A, or in progeny of plants that were mono-telodisomic or ditelomonotelosomic for chromosome 7Aq (13 II + 1 t II or 13 II + t II + t I) but not in the progeny of plants ditelomonotelosomic for chromosome 7Ap (13 II + t II + t 1). Therefore, there is a gene(s) on chromosome arm 7Ap that prevents the production of diploid (2n) egg cells in wheat. In the absence of 7Ap, a portion of the egg cells have 26 chromosomes, which when fertilized with a pollen nucleus with 14 chromosomes, produces progeny plants with 2n = 40 chromosomes. The data also indicated that chromosome arm 7Dp probably contains a second gene that is capable of preventing the production of triploid plants. Key words: Triticum turgidum L. var. durum, polyploidy, aneuploid, triploid, monosomic.

scholarly journals The Development and Meiotic Behavior of Asymmetrical Isochromosomes in Wheat

Genetics ◽  
1997 ◽  
Vol 145 (4) ◽  
pp. 1155-1160
Author(s):  
Adam J Lukaszewski
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Triticum Aestivum L ◽  
Meiotic Metaphase ◽  
Meiotic Behavior ◽  
Pollen Mother Cells ◽  
Chromosome Arm ◽  
Mother Cells ◽  
Metaphase I

To determine which segments of a chromosome arm are responsible for the initiation of chiasmate pairing in meiosis, a series of novel isochromosomes was developed in hexaploid wheat (Triticum aestivum L.). These isochromosomes are deficient for different terminal segments in the two arms. It is proposed to call them “asymmetrical.” Meiotic metaphase I pairing of these asymmetrical isochromosomes was observed in plants with various doses of normal and deficient arms. The two arms of an asymmetrical isochromosome were bound by a chiasma in only two of the 1134 pollen mother cells analyzed. Pairing was between arms of identical length whenever such were available; otherwise, there was no pairing. However, two arms deficient for the same segment paired with a frequency similar to that of normal arms, indicating that the deficient arms retained normal capacity for pairing. Pairing of arms of different length was prevented not by the deficiency itself, but rather, by the heterozygosity for the deficiency. Whether two arms were connected via a centromere in an isochromosome or were present in two different chromosomes had no effect on pairing. This demonstrates that in the absence of homology in the distal regions of chromosome arms, even if relatively short, very long homologous segments may remain unrecognized in meiosis and will not be involved in chiasmate pairing.

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.

The inheritance and chromosomal location of a gene for chocolate chaff in durum wheat

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 229-233 ◽  
Author(s):  
C. F. Konzak ◽  
L. R. Joppa
Keyword(s):  
Durum Wheat ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Recessive Gene ◽  
Single Recessive Gene ◽  
Chromosome Substitution ◽  
Substitution Lines ◽  
D Genome ◽  
B Genome ◽  
Aneuploid Chromosome

The durum wheat (Triticum turgidum L. var. durum) cultivar 'Vic' was treated with the chemical mutagen N-methyl-N′-nitrosourea and among the M2 progeny a mutant with "chocolate chaff" (designated cc) was identified. Genetic analyses indicated that chocolate chaff is due to a single recessive gene mutation. The penetrance of the gene for chocolate chaff was environmentally influenced and varied from dark blotches on the glumes to complete coloration of culms as well as spikes. To determine the chromosomal location of the gene, the mutant was crossed with a set of 'Langdon' durum disomic substitution lines in which each of the 14 A- and B-genome chromosomes of durum wheat were replaced by their respective D-genome homoeologues. The segregation of cc was normal in all of the crosses except for those with the 7D(7A) and 7D(7B) lines. Cytogenetic analysis indicated that the gene was located on chromosome 7B, and that chromosome 7D has a gene that prevents the expression of cc when present in one or more copies. It was shown that the 'Langdon' D-genome disomic substitution lines can be used to determine the chromosomal location of genes in tetraploid wheat.Key words: Triticum turgidum, aneuploid, chromosome substitution, monosomic, cytogenetics.

Plenty Durum wheat

1991 ◽  
Vol 71 (2) ◽  
pp. 501-503 ◽  
Author(s):  
D. R. Knott
Keyword(s):  
Disease Resistance ◽  
Durum Wheat ◽  
Key Words ◽  
Triticum Turgidum ◽  
Wheat Cultivar ◽  
Durum Wheat Cultivar ◽  
Cultivar Description

Plenty durum wheat (Triticum turgidum L.) is a high-yielding, moderately late durum wheat that is eligible for the top grades of amber durum wheat. It has moderately tall, strong straw and is well-adapted to the drier areas of durum production. It is similar to other durum cultivars in disease resistance. Key words: Triticum turgidum, durum wheat, cultivar description

Effect of zinc on cadmium concentration in the tissue of durum wheat

1994 ◽  
Vol 74 (3) ◽  
pp. 549-552 ◽  
Author(s):  
M. Choudhary ◽  
L D. Bailey ◽  
C. A. Grant
Keyword(s):  
Ammonium Nitrate ◽  
Durum Wheat ◽  
Key Words ◽  
Triticum Turgidum ◽  
Cadmium Concentration ◽  
Growth Chamber ◽  
Monoammonium Phosphate ◽  
Chamber Study ◽  
Soil Temperatures

The addition of zinc at 20 mg kg−1 to soils in a growth chamber study reduced the shoot Cd concentration of two durum wheat (Triticum turgidum L. var durum) lines at 10 °C, 16 °C, and 22 °C soil temperatures while additions of ammonium nitrate (NH4NO3) and monoammonium phosphate (NH4H2PO4) increased shoot Cd concentrations. Applying Zn with NH4NO3 or NH4H2PO4 reduced shoot Cd concentrations of the plants to levels comparable to the control. Key words: Cd, durum wheat, ammonium nitrate, monoammonium phosphate, Zn

The three-dimensional arrangement of chromosomes at meiotic metaphase I in normal and interchange heterozygotes of Briza humilis

1990 ◽  
Vol 97 (3) ◽  
pp. 565-570
Author(s):  
JANET M. MOSS ◽  
BRIAN G. MURRAY
Keyword(s):  
Mother Cell ◽  
Three Dimensional ◽  
Meiotic Metaphase ◽  
Central Position ◽  
Normal Plant ◽  
Serial Sections ◽  
Pollen Mother Cells ◽  
Sector Analysis ◽  
Mother Cells ◽  
Metaphase I

Pollen mother cells at metaphase I have been reconstructed from serial sections in normal and interchange heterozygotes of Briza humilis. The pollen mother cells have an irregular shape with a prominent projection from the tangential face into the anther loculus. The seven bivalents of the normal plant are usually arranged with one bivalent in a central position surrounded by a ring of the remaining six or as a ring of all seven bivalents. The central:peripheral distribution of quadrivalents is different in two different interchange plants; in a sector analysis, where cells are divided into four quarters relative to the tangential face of the pollen mother cell, the two plants also show differences in quadrivalent distribution, indicating that individual chromosomes occupy different positions in the cell. The relevance of these results to the positioning of quadrivalents in lateral squashes of meiotic metaphase I are discussed.

Meiosis in triploid Lolium. I. Synaptonemal complex formation and chromosome configurations at metaphase I in aneuploid autotriploid L. multiflorum

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Huw M. Thomas ◽  
Barry J. Thomas
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Lolium Multiflorum ◽  
Synaptonemal Complexes ◽  
Pollen Mother Cells ◽  
Partner Exchange ◽  
Synaptonemal Complex Formation ◽  
Mother Cells ◽  
Axial Element ◽  
Metaphase I

A spreading technique for synaptonemal complexes (SCs) was applied to pollen mother cells of two aneuploid genotypes of autotriploid Lolium multiflorum (2n = 3x + 1 = 22). In the earliest nuclei analyzed the axial elements are in six groups of 3 and one group of 4. Most groups have formed multivalents with from one to five pairing partner exchanges, but there are also groups that have formed bivalents and univalents. Some axial elements have formed triple associations, in one case for the length of the trivalent. Unsynapsed axial elements remain aligned with their homologous SCs into pachytene, but this alignment is abolished as these axes pair heterologously among themselves until the entire axial element complement is synapsed. At metaphase I most chromosomes are associated as trivalents and quadrivalents.Key words: Lolium, triploid, pairing partner exchange, chiasma, multivalent.

scholarly journals Development of pollinium in Malaxis muscifera (Lindl.) Kuntze

1970 ◽  
Vol 39 (2) ◽  
pp. 193-198
Author(s):  
Ravi Kant ◽  
MM Hossain
Keyword(s):  
Key Words ◽  
Vegetative Cell ◽  
Middle Layer ◽  
Cell Degeneration ◽  
Pollen Mother Cells ◽  
Meristematic Cells ◽  
Different Types ◽  
Mother Cells ◽  
Hypodermal Layer

Anther primordium of Malaxis muscifera (Lindl.) Kuntze initiated as a homogenous mass of meristematic cells is surrounded by protoderm. Two thecae are oriented towards the labellum, each of them consisted of a mass of archesporial cells. The hypodermal layer of sporogenous cells divide periclinally to form an endothecial, a middle layer and a tapetum. Pollen mother cells formed different types of microspore tetrads. Each microspore divides mitotically resulting a generative and a vegetative cell. Degeneration of the sterile septum resulted four naked and clavate pollinia. Key words: Malaxis muscifera; Anther; Pollinium; Morphogenesis DOI: 10.3329/bjb.v39i2.7480 Bangladesh J. Bot. 39(2): 193-198, 2010 (December)

Low glucosinolate Brassica juncea breeding line revealed to be nullisomic

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 738-741 ◽  
Author(s):  
B F Cheng ◽  
G Séguin-Swartz ◽  
D J Somers ◽  
G Rakow
Keyword(s):  
Brassica Juncea ◽  
Interspecific Cross ◽  
Meiotic Behaviour ◽  
Breeding Line ◽  
Pollen Mother Cells ◽  
Chromosomal Segregation ◽  
B Genome ◽  
Hybrid Plants ◽  
Mother Cells ◽  
Metaphase I

The low glucosinolate Brassica juncea breeding line 1058 was derived from a BC1F3 plant of an interspecific cross between high glucosinolate Indian B. juncea (genome AABB, 2n = 36) line 60143 and B. rapa (genome AA, 2n = 20) canola strain CZY. Line 60143 had 2n = 36 chromosomes (18 bivalents at metaphase I) and strain CZY had 2n = 20 chromosomes (10 bivalents). Line 1058 was nullisomic, with 2n - 2 = 34 chromosomes, with 17 bivalents formed at metaphase I and an even chromosomal segregation of 17:17 at anaphase I. In F1 hybrid plants of the cross 1058 × CZY, 98.3% of the pollen mother cells had 10 bivalents and seven univalents. This is evidence that plants of line 1058 are nullisomic, missing one pair of B-genome chromosomes.Key words: low glucosinolate mustard, meiotic behaviour, cytogenetics.

Sign in / Sign up

Export Citation Format

Share Document